In 3e/PF, IME Nova tactics for casters can be so overwhelming as to trivialise any conceivable encounter and efectively 'break' the game.
Sure.
But I've not seen any problem with nova tactics in my 5e games.
It wasn't necessarily a /problem/ in 3e/PF (some folks quite liked it), it's just how the game could end up playing.
5e combats are tuned to be fast/trivial, anyway, unless you dial them up pretty aggressively, so it shouldn't make a big difference if you did nova (so why bother?). Plus, almost any class can 'nova' at least a little - the fighter with Action Surge, even the Rogue, in spite of having no rest-recharge powers, can open strong in a surprise round. So if the wizard doesn't pwn an encounter with a big AE, the melee types with scythe through it pretty quickly, anyway.
Does anyone else have this experience, or am I alone? Because it seems like a lot of the angst about the "5 minute adventuring day", "Policing the adventuring day" to force multiple encounters, et al
Oh, the 5MWD issue (and the even more problematic issue of 'balancing' short vs long rests vs encounter & other challenges) still applies, it's just not necessarily all about trivializing combat encounters.
A caster can Nova with a high-damage/big-area/hard-control/whatever spell, a melee type can combo with some peak DPR, they can even synergize and rollover a speedbump encounter that much more easily.
But, because casters are all spontaneous, now, any slot you nova with is a slot you can't solve some other problem with, so the issue with too-short/easy a day is not just that you can blow up every encounter - out of low levels, you can, even on a 6-8 encounter day - it's that you reduce your flexibility to deal with all other challenges if you do so every time. In a shorter day, you not only nova the few encounters as a matter of course, your casters have plenty of mojo left over to trivialize every other challenge you come across.