As a fellow Kirby main, I would like to say the coolest part of this video is the awareness of JeJaJeJa knowing how far Kirby can go before SDing due to going deep spiking them.
Actually, Kirby is. There is a reason why Kirby coming out on top in top tier Tournaments isn't super common. There is a lot stacked against Kirby. You need to be a really skilled player in order to make things look not "all that bad". Jae is just an example of that.
It’s debated wether kirby is high low tier or low mid tier, but mainly due to poor mobility and not a lot of range, and not great (although still useful) specials. Doesn’t mean Kirby’s unviable though, as demonstrated quite well by Jejajeja