Andre, your rationale is broken.

Let's say tomorrow morning block size is 10mb.

I spam it to "full blocks". After all, fees are dirt cheap (even now, 42k txs were processed in the last 24hrs for near zero fees at the 0 to 9 satoshi range - https://bitcoinfees.21.co ) since there's around 0.7-0.8mb actual demand (or at least pretending to be actual by paying 10+ satoshi) and no practical fee competition for the rest 9.3mb.

So once I do that, I come and tell you that there is no room for new users because txs are maxed out.

Spot the fallacy.