As a nasty DM, I always try to let PCs roll for their weakest save. Blindness/Deafness (Fort) to wizards, Animate Rope/Web to Clerics, Hold Person to Fighters, etc. So that is not just a problem of fighter type, if your DM is nasty enough, IMHO.
There are a lot of "save or helpless" spells. That is why any spell casters with more than average wits always prepare some amount of spells which save people from those spells. Say, Freedom of Movement, Remove Paralysis, Remove Blindness/Deafness, Break Enchantments, and the most useful Dispel Magic.
You say fighters cannot go beyond 8th level. But if fighters of your party are killed or otherwise incapacitated so often, your entire party should be annihilated vary soon anyway. In DnD, PCs are expected to work as a team.