If you have a more commercial type server, @Inscrutable’s suggestion is the best. Personally, however, hate world borders and refuse to use them, so I limit Nucleus’ /rtp down to 5k to limit the amount of world gen (Although the start of maps can still be bad), people just reload the same areas over and over. This is also good for people who make custom modpacks, like myself, when you update or add mods which add new stuff to world gen (You can just increase the limit on /rtp to help players find the new stuff). However I have been considering more and more lately of pre-generating a small portion of the map (5-10k), as it would help in the first few weeks. The servers I run however, are small, it’s rare I get more than 12 players on at one time.
Just thought I’d throw in my perspective.