I've been running LVM and Linux software RAID for like 20 years now.
The only limits (for me at least) are:
smallest device in a raid determines size of that array. But that's fine since I then LVM them together anyhow. It does let you mix+match and upgrade though really I always just buy two drives but it helped when starting and I experimented with just LVM without RAID too.
I have to know RAID and LVM instead of trusting some vendor UI. That's a good thing. I can fix stuff in case it were to break.
I found as drives went to Terabytes it was better to have multiple smaller partitions as the raid devices even when on the same physical drive. Faster rebuild in case of a random read error. I use raid1. YMMV
I still have the same LVM partitions / data that I had 20 years ago but also not. All the hardware underneath has changed multiple times, especially drives. I still use HDDs and used to have root on RAID+LVM too but have switched for a single SSD. I reinstalled the OS for that part but the LVM+RAID setup and its data stayed intact. If anything ever happens to the SSD with the OS, I don't care. I'll buy a new one, install an OS and I'm good to go.
I've been running LVM and Linux software RAID for like 20 years now.
The only limits (for me at least) are:
I still have the same LVM partitions / data that I had 20 years ago but also not. All the hardware underneath has changed multiple times, especially drives. I still use HDDs and used to have root on RAID+LVM too but have switched for a single SSD. I reinstalled the OS for that part but the LVM+RAID setup and its data stayed intact. If anything ever happens to the SSD with the OS, I don't care. I'll buy a new one, install an OS and I'm good to go.