hmm . . . i suppose it depends a lot on where you ride and what you ride. take me for example, i'm 48, i have typical UK XC riding around me, a retrobike is fully capable of riding here but i barely ever get them out, i use my modern Orange P7 most which is a 29er frame with 27+ wheels in it with a 140mm suspension fork, it's much more comfortable, takes the hits, doesn't give me back ache, so yeah i'm happy riding modern here more so than retro, for Wales i have my Orange Phase E bike, my Orange 5 and my Orange Alpine6 for the bike parks and uplift days and the Alps once a year so the retrobikes don't really get a look in.
regards road riding, to be honest i have mostly given up! too many idiots going too fast, i only have retro road bikes now, nothing modern, i occasionally ride them to the local brewery, more because they are bling and look great next to the "stealthy" carbon bikes.
gravel bikes, i sort of have one, i tried a few, they ride nice, had an RX9 from orange, bit racey, had a Sutra from Kona, felt too big, tried an Orange Speedwork, felt too short in the toptube, currently got an older kona rove, rebuilt it with GRX, seems ok, but frankly i'll use it more as a utility tourer commuter style bike than an actual gravel bike.
clothes wise, i think you find what works for you, i live all year round in ion shorts and mostly their black tee shirts, the shorts sit just over the knee, loose fit, in black, i wear them in the shop, and on the bike, perfect for me, i don't do bright clothing, and any logos need to be simple or small. i hate high viz even though i understand why people wear it.
having the shop i see what other people wear, sometimes i am shocked, parents that won't wear helmets but insist their kids do, matching high viz couples in their 50's plus, the mid 30's lot that are new-ish to biking or occasional bikers that never wear anything appropriate and have a can of coke wedged in to a crudely bent bottle cage! the kids with helmets hanging on the bars, the pikey with an obviously stolen bike that doesn't have brakes riding towards the shop with a fag hanging out his gob and a can of monster in one hand doing none handed.
yeah people who ride bikes, very odd bunch.