Druids can do well on melee, mainly if they shapeshift.
If you prefer low magic chars, is your preference, but some people don't like melee because they have few things to do. Solution? IMO is to bring cool stuff to martial classes to do. But cripple casters will ruin the game... Instead of an boring experience for people who only like melee, we will have an boring experience for everyone. I can't find ways to make pure martial classes more strong without making then "supernatural"...
And ironic you mention other RPG's, because magic tends to be stronger on other games. Did you heard about mage the ascension? Mages in world of darkness can make even ancient vampires fear in despair. And an archmage can be an god in his own dimension. Tremere that are the closest clan to mages are feared and mistrusted due his blood sorcery that is an very limited version of hedge sorcery... And on warhammer, i never played, but looked into the wikipedia and an lv 1 spell can animate D6 skeletons ( https://wfrp1e.fandom.com/wiki/Summon_Skeletons ) and weapons like crossbows have an good range(if on yard > https://wfrp1e.fandom.com/wiki/Crossbow ), looks like the unique difference is that high level spells doesn't exist on warhammer.
And not all martial classes are bad. As you have said. Monks on 3e are not that bad. Bear Totem Barbarian is not bad. Paladins aren't bad.