This is why the Lightning Network was developed so you can perform transactions that do not require you to use the main chain every time.
LN is not a solution to everything. The points that OP raised, is super valid. The Bitcoin architecture itself is not enough for mass adoption. The network is simply not capable of handling huge amount of transactions.
Lightning network is a side chain. But it also needs to broadcast the transactions through the main chain. If the mempool always remains busy, eventually the lightning network will have to pay higher fees while broadcasting.
There has to be some core algorithm change to accommodate the changing needs of the users.