^This post above. A load of bilge to be honest.
1. It hasn’t been that way for 100 years. EASA came into being in 2002. (I actually didn’t realise it was that old). Any EASA certified pilot or engineer can work on any aircraft from another member state other than their own. Right now, UK certified staff cannot without the equivalent conversion. It’s frankly a nonsense.
2. Although not necessarily relevant, the JAA preceded it. There has been international cooperation since the beginning of the liberalisation of the European travel market.
3. Many regulators automatically recognise/validate licences from other authorities without further certification other than a paperwork exercise.
4. The only difference in the extreme scenario can be on a 737 from another could be a decal on the back and a different reg cert in the folder.
5. Many third country operators and their regulators follow the state of design (Airbus/CFM being French for instance) and/or EASA guidance anyway. The significant majority are not certificating authorities.
6. I would guess that it wasn’t the U.K. CAAs decision to pull out of EASA. I suggest it was the BoJo administration which forced their hand just because it had EU in the name. They certainly weren’t prepared for it. The UK CAA literally helped write the regs and supplied the staff.
7. This is more politics than common sense.