In the 1990s I sat in briefings about how the electronic spectrum was full. We were at the limit of bandwidth and new uses for the internet were a waste of time. Today those who were questioning the limits of dial up internet would look like fools. Things get built as they are needed. There aren’t 8 billion people wanting to transact in bitcoin so your question is unanswerable. Things are being built and scaled on Bitcoin every day. Use what we have (lightning, liquid, cashu, etc) and solutions will grow with demand.