I do not believe that a time will come when bitcoin will be overtaken by another cryptocurrencies. Considering the many factors that contributes to the success of bitcoin as the number one cryptocurrency, you'd realise that no other cryptocurrencies comes close.
If you'd talk in terms of price, bitcoin tops the list. The second cryptocurrency is Ethereum and it just surpassed the $4k mark unlike bitcoin that has a ATH of $63k.
Secondly, talking about adoption, bitcoin has gain widespread adoption more than any other cryptocurrency. This is partially due to the fact that it is the first cryptocurrency and partially due to the fact that quite a lot of top companies are adopting it.
I also think like you. Hardly any cryptocurrency can surpass Bitcoin. This has not happened so far. Currently, the cryptocurrency market has a lot of investment coins that are all profitable. It was previously predicted that ETH will surpass Bitcoin but so far this has not happened.
Bitcoin may have shortcomings like expensive fees and transaction times, but at the moment, they way it is positioned in the market, would be hard to replace. The popularity alone is hard to topple with. But we are always open to the scenario that someday, a better one will come. But for the moment and the next coming years, I don't think another coin will replace bitcoin in its position.