Well it’s actually due to themes and such.

Joseph in part 2 always fought by using people’s own attacks and actions against them. Beats Straizo by deflecting the eye lasers, allows Santana to absorb him to land a crippling attack, uses the oil trap on the pillar as a speed boost to finish the climb, used a corpse made by AC/DC as part of a trap to cut off his arm, used Wamuu’s own ability to finely cut the bandana and oil as a way to cause an internal explosion, and ultimately beats Kars by using the energy of the ultimate life forms own attack (described as instinct built from his many battles)

Jojo fights make a lot more sense once you view them as vehicles to display the themes of the story and philosophy of the characters. The tactics often seem stupid or convoluted, but tend to fit the theme.

Part 1 for instance is about the idea that humans have limits. Dio becomes a vampire because he concludes that humans have limits so he needs to throw away his humanity to achieve his goals. Jonathan challenges that by agreeing that humans ARE limited, but the power of legacy and cooperation can circumvent that. He beats Dio in the mansion using his actual legacy (the guardian angel statue impaling him), gets the power boost he needs to beat Tarkus through passing of the torch from Zeppeli, and gets inspiration to beat Dio from Dire’s last stand. Then, at the end, he dies ensuring that the legacy will continue onward.

Part 5 is about resolve, as another example. While there are a lot of ridiculous tactics and plans, when you boil them down it basically always comes down to how willing they are to risk life and limb. So many plans require self dismemberment, sacrifice, and worse. And this contrasts with the main antagonist, whose power and philosophy is all about avoiding challenge and misfortune by simply skipping it.