What Valorant did is excellent. But they did it in a 10 player arena shooter. This isn’t something that can be done by the average/above average indie dev. Nor is it feasible for all games. For example 32 - 100+ player games on large maps. The compute times would decimate server tick.
Another factor you have to look at is avg player latencies, loss, variance. Some games … Battlefield, CoD, PubG, Warzone etc have player latencies as high as 500ms mixed with pings in the teens or less. With high pings your looking at players being up to 9 frames ahead of the server (outright malicious peekers advantage).
There’s also the issue of audio == update. Valorants system replicates if the player makes a sound that could be heard (within attenuation range). If your game uses a lot of player movement/item sounds (spawn at location), then valorants approach would send an update in these scenarios … regardless if occluded.
e.g. reloading, changing attachments, footsteps, equipment rustling, dropping/picking up loot, equipping an item, healing/meds, firing, throwing an item etc etc.
Everyone of these conditions would fire off a positional update. Which for the most part negates the intended purpose of the replication overhaul. The only time it would be completely effective is if the client didn’t move (but last known still works), or at long distances.
There’s a lot of factors that must be considered to determine if “some x feature functionality” is feasible or not. tech debt, implementation costs, running costs, performance etc.