You can watch the MK fireworks (but not the projections) from CG, or NArcoosees. Or the decks / beaches of most MK resorts. Then there are dessert parties for seeing all of it.
There is one dining package for the EPCOT fireworks, at Rose and Crown, but views can be had from other places on the lake I believe. Then there is the Frozen dessert party, including fireworks viewing and a ride on FEA.
At HS and AK, I believe the light shows are shows, and need entrance. (You can get a dining package, or FP, but I believe neither are *necessary*)
Did a dessert party at MK during the Halloween Party, which includes a reserved standing area to watch the fireworks outside of the Plaza. Wouldn’t do it again. Wasn’t bad, but wasn’t that impressed with the dessert party, and overall, not worth the money.
We did Cal. Grill last year fro fireworks and got an 8:30 ADR as I recall, which was perfect as the fireworks began as I recall around 9:15 (mid March). We chose to sit inside to watch because they pump the music in and they dim the lights. Found no need to go out on the outside space since almost the entire restaurant cleared out to go out there. Was a phenomenal experience, including very good food and wine, albeit the price was obnoxious but that is the mack daddy spot for fireworks view eating at WDW (thinking Topolino at Riviera may be nice too when it opens).
HEA is nowhere near as good from a distance like wishes was, we were disappointed in when we saw it from Sunset Point and California Grill.
I would see it in the park either from a table near Casey's or at a Dessert Party. Even after the recent price increases at the Dessert Parties I still think it's worth the price especially for the terrace seating. I say that even after getting a great spot in the hub for it in our November trip.
There is a "pay to play" option for every show at every park. Some are through dinner/desert packages, some are through Disney VIP services, some are through FP's. You can find info for all options on the official site.