Have you ever noticed how the first few people who log into a Minecraft survival server tend to strip the land around spawn of any easy resources... And build shelter... And put up torches for safety?
Which means the person who logs on a day later, or even an hour later will get a very different experience. And often a less fun one, where there is no scramble for shelter. Or where the coal from that outcropping is just gone.
The original goal was to prevent that by randomizing the spawn location for each player. It's turned out to be even better... The excitement of having everyone experience and want to share the different things they find has turned out to be much more fun than expected.
This is extremely low impact, listening for only two events. On initial login, players receive their random spawn location. Further logins do not use it unless the player dies without a bed. On respawn, players without beds are returned to their personal spawn point.
I've been using it with more than a dozen other mods, and it works well. This is as expected because of the nature of how it works... It just doesn't get involved with much. And what it does get involved with lasts just a few milliseconds and is done and back out of the way.