Can we go down a bit on this?
1. "R.I.P BTC" you said. Will it interest you to know that the fate of all altcoins depends on the success of BTC? No altcoin is trusted as much as BTC. It therefore means that if BTC is to Rest in Peace, the Doge and Eth will aswell rest with the King.
2. You mentioned  Huge Transactions Fee. The highness of BTC fee is much evident in small transactions. The fee will always be bearable for huge transactions. BTC is the king, you use the king to buy a car, then you his fellowers to fuel your car. However, if you so wish to use the king for day to day frequent transactions, you may consider using Lightening Network.
3. You also pointed "Limited Supply" as a defect of BTC. The limited nature of BTC is a purposeful design, infact it's the nature of BTC. It is one of the reasons BTC would always be valuable. BTC is designed on scarcity model. However, it will be advisable if we pay less attention to the fixed supply because the available is not even looking like what we can exhaust in 100yrs to come
4.On Slow Blockchain. The average time for BTC transactions is 10mins, though it varies due to some circumstances. 10mins is not too long for someone buying a Tesla car or someone sending huge money across boarders to wait. Unless you want to use BTC to buy a bottle water on the street while driving. However, if you want a faster transaction time, you can always pay slightly above the normal fee.
Conclusively, BTC is here to stay. It is our duty to improvise, innovate and improve the system and not the other way round.