Mining all the supply means the Circulating Supply increased too so there's a chance that price will drop too.
The supply of Bitcoin is pre determined, all the halving dates are known and barring changes in difficulty, anyone can predict what amount would have been mined at any exact time with close accuracy, with that, I doubt if supply could actually cause a significant drop in the price as it is already priced in, and we are immune to supply shocks. Also majority of Bitcoin has already been mined and only a few are left, which is probably not enough to cause an inflation and bring prices down.
The scalability problem is the main issue of BTC right now and so far, no concrete solution on it. A lot of different blockchain already closed on achieving it so if others can do what BTC can't, it's really alarming what will gonna happened on BTC future.
There are currently several solutions being proposed and implemented to improve scalability, such as schnoor and Taproot. Also, Bitcoin is not in direct competition with other blockchains, it has intrinsic qualities which should always make it valuable, even if not as a currency.
When do you think it'll hit these price targets for the first time?
Sometimes in the future probably. I could take a wild guess, but it's not really necessary to predict the future price. 1
BTC would always be 1
BTC, and at some point, valuing it against fiat might no longer be the best alternative and we would have other means of determining its value.