Why would the EU want to incur any cost to cater for non-EU citizens wishing to visit the EU to pay by cash? It is so niche as to be not worth considering. Those people can stay in their own country - no-one has any right to go to another country.There are plenty of people without bank accounts. You can pay for your travel with cash. I do it all the time. All of the ferry ports take cash. Eurostar take cash at their stations. Most hotels take cash. Although it is less common there are still many people without bank accounts and if they are going to be introducing this ETIAS visa they really need to have a facility to pay cash. Although i suspect it will mean having to go to the embassy and get a full visa to pay cash.
The Electronic visa scheme allows (a) a check against a database of undesirables, and (b) automatic checking to comply within the 90 days in 180 rules.I am not sure it does. It takes one second to stamp a passport. It maybe adds one second extra. They have to look at your passport and look at your photo page anyway and verify that you are that person and that surely takes up more time than stamping it.
Anyway is this new ETIAS visa thing actually getting rid of stamping? Even with the ETIAS visa you are still only allowed 90 days within 180 days so surely they will still have to stamp it every time you enter and every time you exit?
No need fore stamping, the database will know and check.