Make Blob sizes dynamic ?

Perhaps a noob question but:

Pectra is supposed to increase Blob sizes to accommodate more throughput and lower fees, however this will hurt the holders (less burn until more througput comes in).

Why can't we make Blob sizes dynamic?

- Increase in size (automatically) when demand is needed and decrease it when demand is low in order to strike a balance to allow a healthy - constant burn of Eth.

Wasn't Ether supposed to be Ultra sound money?

I know we need to attract more projects to join in as L2s (by having lower fees), but if other L1s take "our cake" before we achieve our objective, we won't attract more L2s either ways.