There have been lots of suggestions relating to stamina class skills, ranging from morph changes, to 3 morphs, to passive morphs. The base problem is that zos did not understand the impact of 1.6 across the board and hence completely destroyed a number of fun and viable builds overnight - leaving a relatively small number of cookie-cutter builds remaining. Until zos realise this and realise what soft caps did wrt supporting hybrids and balance in general, we are likely to have a vast array of issues... because the game was originally balanced around soft caps. Now add in CPs and its a mess frankly.
The best option for zos would be to work on a complete overhaul of the skill system and CP interaction in the background. However that isn't likely to happen. The most elegant solution I have seen on the whole topic is to base the effectiveness of abilities off weapon and spell power only - making stamina and magicka resource pools with no impact on the actual abilities effectiveness. Why is this better? It keeps power creep to gear (ie weapons and +spell or weapon power) and CPs (ie mighty, etc). It also means that the base weapon will always provide a decent level of scaling for stamina builds using magicka abilities and visa-versa (just look a magicka builds that use dual wield because the get a greater spell power to understand why, but also weapon vs spell power rarely gets worse than a 2:1 ratio rather than a 5:1 ratio). It makes hybrids viable and makes niche sets with spell and weapon power a viable choice.
So if effectiveness were linked only to spell and weapon power, you could probably live without a number of stamina morphs as all class abilities would hit reasonably hard (and harder if specced for) - although I am not generally advocating that all class skills are returned to be magicka based. The skills would cost a set resource but their effectiveness would be based on spell or weapon power as appropriate (and thus unchanged compared to current as a starting point).
It would probably mean the end of max stat meta and racial dominance by max stat races as well.. some might require a compensation tweak tbh... Maybe in the same timescales that Argonians got theirs
. It would also mean that some skills would need to be changed to be effective (such as bound armour).