The 5-round draft PLUS the $20,000 limit on other bonuses. I think MLB saves $30 million total on the slots from rounds 6-10, but I imagine the $20,000 limit (vs $125,000) saves much more. The Phillies had $2.6 million in bonuses after the 10th round in 2019. While that might be a little above average for the league, it probably averages at least $60 million. So MLB is saving at least $90 million here.
The result is a lot of 23rd round draft choice types will give up baseball. Or consider other sports. The NFL did not lower draft bonuses at all. Colleges won't have additional scholarships for kids staying in school. The loser here will be baseball in the long run. They could have kept the draft at 20 rounds, frozen the slots at 2019 levels. Even dropped them 10%. And kept the $125K limit on other bonuses. That would have kept these kids playing baseball and helped the game in the long run.