That and a lot of people aren't actually playing 5.5. Just grinding old axes.
Inter class balance is really good imho at least at levels that matter.
The power creep is very real though phb to phb. Depending on what's allowed from Tashas though that gap may not matter as much.
5.5 may...
Well one way you could do it.
1. Cantrips. You can add riders onto them.
2. Level 18 wizard ability comes online at level 6. Lvl 1 spells only. You can cast them at will. Level 2 comes online 12, lvl 3 18.
3. 2014 book of shadows
Ritual caster, good cantrips, good at rituals low level...
Very mixed responses.
RAW it seems to be a yes though as an upcast spell is aspell of that level.
As mentioned earlier.
Reread the rules.
Cure wounds is an artificer spell. Infused item qualifier.
Upcasting it makes it a level 3 spell.
RAW you can stick it in an item it seems.
If anything i think the 1999 data woukd trend towards even shorter games now.
I strongly suspect the average gane is a few sessions in the lvl 1-7 range. WotC has basically told us this.
Then as now I also suspect the vast majority of gamers are casuals.