It's a bit paradoxical to call something "adaptable" that is so resistant to change and prioritizes ossification and immutability (also can be a good thing).

Bitcoin security budget is a valid concern. There are 3 possibilites:

1. Bitcoin transaction fees become too expensive for everyday transactions so most transactions move to L2+

2. Bitcoin changes it's protocol to expand blocksize and/or increase bloick subsidy.

3. Security falters and the bitcoin expirement fails.

#1 seems the most likely to me, but comes with trade offs different from L1 . L2s are abstractions of bitcoin afaic and not true bitcoin. #2 would break one of the most important value props of bitcoin.

Me pointing out criticisms doesn't mean im anti bitcoin btw. I know Monero has it's own set of trade-offs and is not perfect.