I am here to learn about the safety benefits of IR.
Really? Because it kinda looks like you're here to look for reinforcement of your lack of desire to fly IFR - You said you're a day VFR pilot and plan to remain that way. That's fine, but don't think that getting the IR wouldn't make you a better pilot in the generic sense.
Now... Do you fly a Pitts and do aerobatics? Well, an IR is probably not going to make you better in that case, if you're good at aerobatics. Flying a plane like that with those kinds of maneuvers demands even more precision. But for the average pilot who flies average spam cans and does leave the pattern, the IR will sill make them a better pilot.
FWIW, that's pretty well true of training in general. Post-PP, I've gotten my instrument, commercial, and multi. I've done several aerobatic lessons, I've taken a mountain flying course, I've gotten a job flying turbines, helped a company get a 135 up and running, and become a Director of Safety knowing absolutely nothing about any of it to start with. I've read a gazillion accident reports. All of that has made me a better pilot in one way or another.
I've also read a gazillion PoA posts, and that has made me both better and worse.

But I've learned a lot of things from people over the years. Ron Levy,
@bbchien,
@John Collins,
@midlifeflyer,
@Larry in TN,
@Bell206,
@wanttaja,
@Dan Thomas,
@Ted, and others have been particularly interesting/helpful/educational. And if I ever go crazy enough to try to (re)build an engine or airplane, I'll definitely be coming back to
@Jim K's greatest hits, which I also enjoy even if only to live vicariously through him.
Whenever this topic comes up, the loudest people are those that are very strongly opinionated that IR makes you a better pilot. I disagree, based on reading 100s of crash reports over the years.
Show me one crash report where NOT having an instrument rating would have led to a better outcome.
However, I do not have data to support my opinion.
There's a reason for that.
That said, going through the mounds of data to make the assertion that it is safer is a significant time investment. The ones who'll benefit from that are the insurance companies. And while there are situations where having an IR does not confer any benefit (such as the Pitts example above), the IR will get you a discount a lot of the time, and it will sometimes be a prerequisite to obtaining coverage. Do you have 4,000 hours of VFR with no accidents or incidents in a Citabria? IR probably won't help you. 200 hour pilot looking to get into a Cirrus or Bonanza? Not having it might get expensive. 200 hour pilot looking to get into a TBM? It'll be a requirement.
1. What is the definition of a better pilot? Are they safer, better at maintaining altitude and heading w/out an AP, have better landings, or something else?
All of those things would point toward a better pilot... But I think the ones that really matter, aside from the obvious "can fly into less than ideal weather and have much less chance of crashing", are things like being more procedure-oriented. When forgetting things can kill you, you tend to be better at following procedures, which tends to help with putting the gear down before you land, for example.
The most important thing to me - The thing that will make me comfortable putting my family in the back of your airplane - is the decisions you make. I'll want a certain amount of stick and rudder skill, of course, but I also want to know that you'll properly assess and mitigate risks, make and execute backup plans, all that sort of thing.
- I am a daytime VFR pilot, and plan to remain that way (I think flying at night and IMC is more risky)
Of course it's more risky. Being rated removes much of the risk, but knowing the system inside and out and learning more about weather and maintenance and all that allows you to more accurately assess and mitigate the additional risks.
In fact, being instrument rated can help you be much safer at night VFR; should I ever become a CFI one of the things I plan to do with my students is to show them the basics of IFR flight planning to help them be safer at night. For example, there are airports even here in the relatively flat Midwest that have significant terrain nearby... And rocks aren't lit. It's VERY worthwhile when flying at night, even if VFR, to read and follow the IFR obstacle departure procedures until you're at an IFR-safe altitude, use IFR-safe altitudes en route, and potentially even use an approach procedure to help get you down safely depending on safe altitudes/terrain/obstacles in the vicinity of the destination airport.
- Juan Brown (Blancolirio) is an ATP, yet only flies daytime VFR in small planes (see
this video at 11:10). That was an interesting statement.
Meh, I've seen lots of airline pilots who think that way. Would I rather be flying a multiengine transport category jet when conditions suck? Sure. Does that mean you can't be reasonably safe in a piston single at night or IFR? Not at all.
Kinda reminds me of the joke about the retired airline pilot going back to flying a 172. He calls up the tower and says "I'm ready for takeoff, and I'd like to declare an emergency." Tower says "What is the nature of your emergency?" and he replies, "Well, I'm down to one engine and my First Officer is missing!"
