He wasn’t doing anything of substance whilst in base against any of those opponents except taking a beating or hiding, what makes you think things would be different here especially after he had to be carried around by Zoro? He’d get utterly molly whopped in a locked octagon with no help.
Definitely you didn't read the manga.
Fought for hours in Base/G2 against Cracker and Katakuri.
Doffy needed dozens of awakened arrow thread strings in the same place to be able to pierce through his Haki and he as well recognized his speed but he was lacking power, nevertheless that speed was the only thing he needed to keep up and have a good fight with Doffy.
He tanked Hybrid Lucci's Rankyaku, could avoid some of his attacks in Base, clashed with him equally and tanked those flying shigans, Lucci was far from doing any relevant stuff to him or overhelm him despite Luffy being in base.
Like I said, you didn't read the manga. Luffy is strong enough to keep up with the bosses in Base form.
And in this fight, he avoided Kaido's Thunder Bagua, while in Base, surprise!!
So no, he does not get "whopped", pure nonsense and headcanon.