What's preventing Bitcoins from being accepted as mainstream payment forms? I'm working on a new blockchain and would like to learn what drawbacks of Bitcoin urgently need to be improved

Do we have any update on this plan? Was this realized? Or it simply did not materialize? It seems that until now Bitcoin's blockchain is still the most efficient and widely used. As far as drawbacks are concerned though, we have already heard and read over and over again the complaints against fees and slow confirmation time. Aside from that, we also have to face the fact that Bitcoin-accepting shops are not as ubiquitous as we would like them to be.