I think anyone who has lifted or worked out understands that maintaining level is far easier than building up.I get you won't be playoff-ready with a ton of rest days, but you also can't be flat out all the time and expect to be anywhere close to peak for when it matters most.
I'm not going to pretend to have watched the Knicks enough to know what Thibs did but I just see all this criticism of him playing too many guys but on the other hand I also see a bunch of teams that aren't physically prepared for the playoffs and to play every other day(I've seen a couple guys complain that every other day is too much) because guys are constantly getting off days and load managed.
Maybe some teams are already doing this but I really think they should start building that fitness in the regular season. For example, first 20ish games you slowly get guys back in the flow and start building up minutes. Second 20ish games have some off days to keep guys healthy but still playing starter type minutes and continue building the workload. Third group of 20 games you go all out and play your guys playoff style minutes in before tapering off the in the final 20 and just maintain that level(get your guys some rest days before the play offs and mix in the occasional 35-40 minute game).
Obviously, injuries happen and you would likely need to tailor this to individual players that get banged up and miss time but the general idea is just to utilize the regular season to prepare for long grueling playoff series.
Now a lot of teams are fighting for a spot and don't have the luxury of pulling their foot off the gas towards the end of the season but most of the top teams and true contenders should be able to.