Lucky you, you got Da Bears! ;)
That's exactly right. Each season has an entirely new cast of characters, writers, directors, artists, music, etc. So each season has it's own unique look, style and flavor.
So Fresh Pretty Cure (season 6) is different from Suite PreCure (season 8) and so on.
There are two exceptions. Season 2 Futari Wa Pretty Cure Max Heart reprised Season 1 Futari Wa Pretty Cure. And Season 5 Yes Pretty Cure 5 GoGo reprised Season 4 Yes Pretty Cure 5.
To be fair, Seasons 2 & 5 can be watched without having seen the preceeding seasons, but you miss a lot of the "in jokes." And you don't need to watch Seasons 2 & 5 to enjoy Seasons 1 & 4.
And there are the PreCure All Stars movies which bring back ALL the Cures for grand adventures.
The underlying premise behind it all, is that when evil threatens the world, Legendary Warriors (Pretty Cure/PreCure) will appear to save us.
Each season has it's charms, and all are worth watching, but it's not surprising that some seasons are better than others. Hence, my suggestions for season viewing. IMO, the four best seasons, in no particular order, are:
4 Yes Pretty Cure 5
6 Fresh Pretty Cure
7 HeartCatch PreCure
10 DokiDoki PreCure