Have you checked out PF2e? It is surprisingly also a take on lowering caster power. Lower level casters are even arguably too weak and could use a little boost. Casters catch up and seem fun to play at levels 7 or 9+
It does have some stuff I don't like -- older vanican casting, skill feat gates, a few too many modifiers, etc. -- but it is certainly a better take on caster / martial balance than 5e.
Like 4e, the Fighter is not particularly mythical at higher levels -- they have just tamped down the power of casters especially against "boss" higher level then party types and given the Fighter some tricks to shore up it's traditional weaknesses like a feat to down fliers, etc.