My tabletop experience is actually the same. It's very often that spells don't connect. But it's also quite frequent that attacks miss. However due to the overabundance of advantage weapon attacks has a big leg up. I'd say the preferred solution is to dial down on the plethora of available advantages, and rethink exactly what level and gear they build their encounters with.
Larian has made all enemies you meet of similar level. They're all level 4 in an area. I would never design it that way, I'd have maybe a level 4 boss that has some beefy AC and saves, accompanied by some level 1-2 grunts which can be more easily handled with AoE spells. Unless Larian changes their approach to encounter design and varies the level of enemies more within the same encounter, I fear that both damage and control spells will be pretty lackluster.
