Completely agree with you, mate. High fees and slow speeds, is what will kill Bitcoin in the long term since it makes payments impractical. However, this may change soon as the Lightning Network becomes active within the Bitcoin network to reduce fees to a minimum and provide near-instant transactions. This might bring back people which used altcoins for lower costs and faster speeds. In effect, Bitcoin's market dominance would be greater as many altcoins would be rendered useless due to the Lightning Network's unrivaled speeds.
Those altcoins which implement the Lightning Network too (like Litecoin and Vertcoin), would see a major boost in scalability like Bitcoin. Therefore, it's safe to say that Bitcoin will eventually scale to a wider audience, promoting greater adoption in the mainstream world. Bitcoin will be cheap and fast like it did in its early days. Just my thoughts