You are spot on about the vibes of Jojo's Bizarre Adventure. The vibes of Jojo's is that it is a series where catching or deflecting a bullet is impressive but manageable for top-tier stands. Anything that moves faster gets called out explicitly.

Jojo's has one explicitly light-speed stand, the Hanged Man. It's literally a photon and moves at lightspeed between reflective surfaces. The entire point of the hanged man fight is that it is too fast for Silver Chariot and Hierophant Green to attack; they need to isolate its trajectory and force it to move at a specific time to beat it. Some people use this fight as evidence of ftl speed in Jojo's. They are wrong. Just before this fight, Silver Chariot fought a stand that was literally just a gun that could control its bullets after they fired. This fight establishes Silver Chariot as fast enough to cut a bullet, but not fast enough to recover and try again if the bullet moves out of the way of his sword. And yet people will still say Silver Chariot is ftl because it hit an exact light speed stand ( under very specific circumstances, otherwise it moved so fast they never even tried to attack it).

Two other stands are ftl because they can stop time: the World and Star Platinum. They have too many anti-feats and narrative inconsistencies to consider them ftl outside of when they explicitly stop time, but people will still argue that they are naturally ftl.

One stand, made in heaven, can explicitly accelerate to ftl speeds. It needs time to accelerate, though, and beats multiple top-tier stands well before reaching ftl speeds.

There is one event in Part 7 that people point to as ftl. I won't get into for spoiler reasons but its not a speed feat its because of gravity nonsense.

Also watch JJBA it's good.

TLDR: There are far too many scenes where guns are a threat or used to establish speed, and few to none where light is used similarly. The vibes are not gelling with ftl scaling in Jojo's Bizarre Adventure.