Just cheap writing. Oda just wanted to hype up Shanks. Whoever Shanks first on screen opponent was, was always going to get stomped just for shock value and hype. Unfortunately, it had to be Kidd.
You are technically correct, although the reality is a bit different.
Kidd stood no chance from the beginning. He got his ass high up after Big Mom stuff which wasn't concrete 1 vs 1 or even 2 vs 1.
Oda simply baited Kidd fans into believing he is among the big players.
This "New Generation" bullshit needs to be stopped.
Not everyone is/will be Luffy.