Yes it's OK to wear diapers for comfort or just because you want too.
There's no age limit to wearing diapers and if you want too or need to wear diapers as a kid, teen or adult etc you should.
You should do what makes you happy and if wearing diapers and using diapers makes you happy then you should wear the diapers and use them.
For some people the diapers give the person comfort and make them feel good.
Wearing diapers can also be convenient when you're out in public and cannot find a toilet.
If you need to pee or poop and are not near a toilet or the toilet is not available then you can pee and poop in your diaper and then go about your business.
Diapers are very comfortable and even more comfortable than underwear.
I started wearing diapers out of convenience when I was away from home because sometimes I would go shopping at a store and there would be no public toilet available and I always had to pee.
Or when I go to festivals etc I can just pee in the diaper and not have to worry about holding the pee in to find a restroom.
I am now a diaper lover and although I don't wear diapers all the time I do wear diapers when I feel like it or when I get away from the house.
I also wear diapers when out camping or when I go on road trips.
Wearing diapers on road trips makes the ride more comfortable because the thick padding of the disposable diaper is nice and when the diaper swells up from pee it makes it even more comfortable.
Sometimes there can be several miles between rest areas or toilets and I need to pee so I just pee in the diaper on the road trip and then change later.