all of which add needless complexity to the rule book in the hope that blowing out a few relievers' arms results in more hits
I'm not sure where you're getting the idea that more relievers would get hurt. If anything, this expectation that guys be ready to throw 25 max-effort pitches multiple times per week (plus however many times they're warmed up and not used) is worse. There were 38 pitchers last season with 70 or more appearances, 8 with 75 or more. In 2017, there were 32. Of those 32, 8 also had 75 or more. That level of usage ruins guys.
Of those 8 who made 75 or more appearances in 2017, six of the 8 spent time on the disabled list in 2018. In 2018, their ERAs were as follows: 4.45, 5.93, 3.22, 4.50, 3.58, 6.00, 4.85, 6.26. None of them exceeded 4 in 2017 (which of course partly explains their heavy use). The 3.22 is a LOOGY and the 3.58 was coming off a 1.78 season in 2017.
If managers can't manage with the expectation that they can use 4 or 5 different relievers every day, they'll adjust the usage patterns back to what it used to be: longer stints less often.