It is proven and tested that Bitcoin is a good investment in the long-term and that cannot be denied, and Bitcoin has many features that other cryptocurrencies do not have, even if it is used as a payment option online it is a big deal how much more even with the opportunity it gives to people. In addition to this it also provides savings in the future, so the scalability that you are talking about is only a low percentage of the problem that a bitcoin holders will face honestly in my opinion.