Motorcycle jacket searches are huge in the US because Amazon dumps fashion leather next to real riding kit. A riding jacket has CE-rated armor at shoulders and elbows, a pocket for a back protector, and a closure that stays shut in a slide. A fashion jacket does not.
Leather abrades longer. Textile is easier to vent and waterproof. Mesh motorcycle jackets are the US summer default; they still need armor, not foam pads. Look for CE Level 1 or 2 on the armor labels. AAA/AA garment ratings (EN 17092) are the current European standard showing up on US shelves.
Fit: snug with a base layer, long enough to cover the belt when you reach the bars, sleeves that do not ride up. A jacket that flaps at 70 mph is the wrong size.
Do not buy used armor that has already taken a hit. Replace after a crash. Pair with gloves and a DOT helmet — the jacket is not a substitute for either.