Accessibility feels like a speed bump in your agile process.
Yeah, I get it. You want to move fast, but keyboard navigation, colour contrast and semantic HTML keep slowing you down.
Here's the reality. If your sprint doesn't incorporate basic accessibility checks at least, you're not agile, you're just sloppy.
You say you'll fix it later, but later never comes.
You complain that it's too much overhead, but why then do you always have time for pointless refactors and that one more thing that came out of one person asking "what if?"
You push back saying you're iterating. While you iterate, real users are stuck with a product that doesn't work for them.
Agile is about delivering value quickly, not shipping half-baked garbage. If your team can't build a button that works for everyone, you're not moving fast, you're failing fast.
Stop whining about speed bumps. The only thing slowing you down is your own refusal to do it right the first time.