Where can I watch all seasons and episodes of Pokémon?

During the Corona period, of course, you have a little more time, especially with the possibly even sharper lockdown: For this reason, I ask where I can best watch everything from season 1 to the most current season, preferably on one platform.
I've seen season one on Netflix, but then it's only season 17 or something.

It would be really cool if someone could recommend a site to me.

There's no legal provider that has all seasons / episodes.

But the following providers have parts of Pokémon on offer: Pokémon TV, Netflix, Amazon Prime Video and TVNOW

I was just watching Pokémon TV and came across this: https://www.pokemon.com/de/pokemon-folgen/pokemon-tv-staffeln/
These are all seasons and episodes, aren't they? So are they complete etc?

Yes, all seasons are listed in the episode lexicon, but there's not a stream for all of them.
Take a look at seasons 2 and 3, for example.
https://www.pokemon.com/de/pokemon-folgen/pokemon-tv-staffeln/staffeln-2/
https://www.pokemon.com/de/pokemon-folgen/pokemon-tv-staffeln/staffeln-3/
In season 2 there's a play symbol on the thumbnails of the episodes, as these are available as a stream.
For season 3 the thumbnails are shown without the play symbol.

https://watch.pokemon.com/de-de/#/category?id=series
https://watch.pokemon.com/de-de/#/category?id=specials

But are the episodes in season 1 complete?

Because on some pages I see that the season 1 to episode 82 goes with the name: "The promise"

A few episodes are missing because they never appeared in Germany.

E.g.
https://pokewiki.de/Aopulco_no_Ky%C5%ABjitsu, because here you saw James disguised as a woman in a bikini and this was classified by the prudish Americans as not suitable for children and this episode therefore never came to Germany.
https://www.pokewiki.de/Miniryu_no_Densetsu was also classified as unsuitable for children due to the massive depiction of violence, including handguns or torture.
And https://www.pokewiki.de/Denn%C5%8D_Senshi_Porygon, because a rapid flicker of colors could be seen here during an explosion, which in Japan led to epileptic seizures in children. This episode was therefore not broadcast again even in Japan.

You can find a list of such episodes here:
https://pokewiki.de/Nicht_ausgestrahlte_Episoden

There are different divisions regarding the episodes of a season.

Some pages see the entire original series, consisting of 276 episodes, as a contiguous season. This then includes the Kanto and Johto story.
https://www.anisearch.de/...s/episodes
https://myanimelist.net/...on/episode

Others split the 276 episodes of the original series into multiple seasons
In the PokéWiki this is divided into 5 seasons, with the first season having said 82 episodes.
https://www.pokewiki.de/Originalserie
On the official Pokémon website it is also divided into 5 seasons in the episode dictionary, but here the first season only has 52 episodes (or a few more if you add the missing episodes).
https://www.pokemon.com/de/pokemon-folgen/pokemon-tv-staffeln/staffeln-1/