There may be fewer players than before, but so what? There's enough people playing that you can always find someone to race against.
And you don't always have to race someone.
Some people like this, driving about like you're in a town, sometimes playing cops and criminals, doing tasks for money, etc. Not my thing, so I don't bother with these. But lots do like this. I suspect was not thought of as an option by anyone when LFS was being developed, but it's popular, and the only racing game I know where you can do this.
Some people are good at this, and happy to spend lot of time on drift servers. Sadly, I'm not good. Don't have the skill. If I did have, then likely I could drive some of the cars that want to oversteer a lot better than I can actually do.
Lots like this, but it helps to have good reflexes and technique. Both well beyond me now
Be creative, and make your own. Or drive on other peoples. Or both. Lots of varied and different types, from placing objects on an empty car park, to driving on layouts that involve the roads that surround tracks.
Think you're fast? Prove it. Over a thousand car/track combinations to try and set a world record or two.
Top Gear type challenges
People have built tracks in the sky, have developed soccer games with cars (before there was Rocket League), loops, jumps, etc.
Lack of caravans is a bit of an unfortunate omission as far as some of us are concerned.
Some people like getting involved in the administration of servers. Or video making for youtube and other platforms. Or making websites for teams. Programming to interact with game via InSim (e.g LFSLapper, Prism, etc). Making car skins. Changing object textures.
And of course, there's always the racing. Bigger the license you buy, the more choice of both car models and tracks (and associated multi layouts). And access to Rallycross and go-karts.
Or mix and match
Me. I rent a server, designed and made my own Autocross layouts, load these on my server to set lap times and score (very low) drift points, and do some coding scripts that I like to have on my server.
I haven't found any other game, never mind racing simulator, where I can do all this. And am still interested in doing this over 10 years since I got S2 license.
I've just worked out that LFS has cost me 5p a week (= £2.57 a year) since I first bought a license! And in that time, I've done in excess of 44,000 laps, over 350 hotlaps (sadly, no WR's), designed and made, and made public, a large number of autocross layouts. And compared to a lot of people, these stats are only middling.