If you want to know why the TOS movies were better, just look at the plots: the stakes were higher!
TMP - stopping Earth from being destroyed
TWOK - stopping the Genesis weapon
TSFS - ok, not very epic except for getting Spock back
TVH - saving the whole universe
TFF - Enterprise getting hijacked, kinda interesting
TUC - peace between Federation and Klingons
To be fair, TVH was NOT about saving the whole universe, rather Earth. The remainder of the universe was presumably safe from the Whale Probe.