Earlier quoted context omitted.
It’s practically impossible to use Bitcoin as digital cash because it’s so slow and expensive. That was the original problem it purported to solve, but it failed miserably at that.
So far. If you spend any time in the research community you’ll realise that those problems are very likely to get solved. Lightning alone probably gets us there. Its volatility and UX, as well as how negatively it is perceived currently (by some people) look like bigger blockers to me.
Which that is not Bitcoin and neither is it on-chain.
The parent comment is correct on Bitcoin's failure as a peer-to-peer electronic cash system and all it is instead, is a store of value. This is how you know it has failed in its intended purpose.