Even if we assumed your assumption was correct:

Let's assume an average $12 fee now (probably will drop back to lower levels)

$200 - $12 = $188

If we assume your thesis that fees will increase at the same pace as the savings:

$20,000 - $1200 = $18,800

Yeah, I'd rather have $18,800 stored safely on the base layer, vs storing that amount on L2. 

 Now less than a week later the average fee is around $4 - $5 per tx.

In the above example with a 100x increase in both exchange rate and transactions:

$20,000 - $450 = 19,550. 

 Math 4 the win 🏆 

 Just had a look at the mempool today and the average tx fee is $1.61.