My Quick Thoughts on the No National Pokédex Controversy

Serebii.net has listed all the Pokémon currently in Pokémon Sword and Shield here.

To recap, only Pokémon in the Galar Pokédex can be transferred into Pokémon Sword and Shield; not all of the 809 previous Pokémon will be in the new games. This has sparked a lot of controversy in the Pokémon fanbase.

To be honest, I don't like this idea either because I'm used to having every single Pokémon from previous generations in a main series Pokémon game, but I still respect GAME FREAK's decision.
Interestingly, however, I think I'm not as bothered by the lack of a National Pokédex as some other people, and here are my quick and lazy thoughts as to why.

First off, I've played Pokémon Prism, a ROM hack of Pokémon Crystal. Due to technical limitations, Pokémon Prism only has 253 Pokémon; some Generations 1 and 2 Pokémon were replaced with Pokémon from Generations 3 and 4 plus Sylveon and a few fan-made Pokémon.
Admittedly, I have difficulty making up a "best team" for Pokémon Prism in the style of the Pokémon YouTuber MysticUmbreon, but I still enjoyed the game despite the limited team options. There were several other redeeming qualities in the ROM hack such as the Generation 4 physical/special split.
In other words, I can still enjoy Pokémon Sword and Shield with limited Pokémon choices (assuming I can actually play it) because I've played a ROM hack that did the same thing.

Second, I think there will be other ways to play with a full National Pokédex--yes, including the Galar Pokémon. These are Pokémon Showdown, Pixelmon, and a hypothetical Hytale Pixelmon.
I don't own a Nintendo Switch, and neither I nor my parents have the budget to pay for a Nintendo Switch. (Plus, my paternal uncle is just as stupid as my paternal grandma.) But we do have a PC, and my mom and dad are willing to buy me Hytale.
Pokémon Showdown is a Pokémon battle simulator from Smogon that can be played on both PCs and mobile devices (using an Internet browser), while Minecraft and Hytale are both PC games.
Additionally, Pokémon Showdown has a Custom Game feature which has very few restrictions--heck, Pokémon can be given moves they can't learn! I think it's likely that it would also allow the whole National Pokédex.

A Custom Game in Pokémon Showdown. Note the illegal moves on Magikarp.

Third, some of my favorite Pokémon, including the Ralts and Roselia evolutionary lines, are in the Galar Pokédex. 'Nuff said.

Behind the Scenes: I was gonna say I'm more bothered about Fire Emblem: Three Houses not having a weapon triangle, but I just found out that weapon breaker skills can be learned by improving skill in a particular weapon; for example, Axebreaker can be learned by improving sword skill.

Edit, November 21, 2019:

Yes, you can battle a Gigantamaxed Pokémon with a Mega Evolved Pokémon, among other crazy things.