Are fender flare gaskets necessary on a 2002 Tacoma TRD?

One by one they are stretching out and falling off. They don't seem to be causing a rattle, and as far as I know the truck is made to either have flares or not, so are the gaskets really needed?
There are aftermarket kits with adhesive tape attached but they look like they might be hard to put on without removing the flares. On a 21-year-old truck I'd rather not mess with plastic parts any more than I have to.

 

I removed a single flare once to have some body repair. I don't recall any gaskets. (2002 Tacoma Prerunner)

 

Other than preventing water from sitting inside the flare, they aren't needed. They were peeling up on the ends of my '01.
Sealed the ends of some. 1 came off completely so I left it. Older truck. Didn't care.

 

That and vibrations are the only real function that they serve. When driving the plastic can vibrate against the body of the car and scratch up the paint where it's rubbing. Junk gets stuck inside of them too since there's nowhere for it to go. Stuff like pine straw, road debris, etc. They have rolls on Amazon for like $20 that are big enough so you can replace all 4 - all you have to do is measure and cut.
If you do choose to go this route make sure you buy the red and blue body clips (they're single use anyway so they're meant to break) and take a picture once you remove the flare. The color orientation is important. The flare itself is unlikely to break unless it's color matched (don't flex the paint by bending too much) and even then they're pretty sturdy in my experience.

 

If you live where Winter Chemicals are never used you should be fine!

In this area any place that can capture moisture in a few years will be rotted away behind the flares.

 

Silicone caulking via caulking gun, to match the flares...looks nice, seals out better than those gaskets