True. Am I the only one that expects a sequel to take under 4 years? BotW2 could have been out in 2019, similar to how Majora's Mask quickly followed up Ocarina of Time. BotW2 is taking so long to make that I won't be satisfied unless it massively builds on the first game. A simple paint by numbers sequel isn't going to cut it anymore.
It's Nintendo, which means two things:
1) They absolutely won't release a game until it hits their threshold for quality. Generally speaking this is great and is why their games are revered decades later.
2) They will intentionally hold back releasing games until they think it makes the most financial sense. There have been plenty of examples of this.
Botw 2 was just gonna be dlc, then they decided to make it a full game. Absolutely they could have (and possibly did) finished it a while ago, but I predict they intentionally kept it from releasing until this year to boost Pro sales.