I do that + script to auto resize within sane limits. So for most servers the partitions will automatically fit the usage while still leaving some spare space.

Usually something like "expand if there is less than 5% left, with monitoring triggering when there is 4% free space left", so there is still warning when the automatic resize is on limit

carving space per PV like that is pointless

> It also serves to leave some space unused to help out the wear-levelling on the SSDs on which the RAID array that is the PV¹ for LVM. I'm, not 100% sure this is needed any more² but I've not looked into that sufficiently so until I do I'll keep the habit.

YMMV but most distros set up a cron/timer that does fstrim monthly. So it shouldn't be needed, as any free space will be returned to SSD.

> [1] if there are multiple PVs, from different drives/arrays, in the VG, then you might need to manually skip a bit on each one because LVM will naturally fill one before using the next. Just allocate a small LV specially on each and don't use it. You can remove one/all of them and add the extents to the fill LV if/when needed. Giving it a useful name also reminds you why that bit of space is carved out.

other options is telling LVM this LV is striped (so it uses space from both drives equally), or manually allocating from drive with more free space when expanding/adding LV

Not needed. All your unused/unfilled space is that space for wear-leveling. It wasn't needed even back then besides some corner cases. And most importantly 10% of the drive in ~2010 were 6-12GB, nowadays it's 50-100GB at least.