If it is as stupid as the situation in the UK, where the UK government quietly (amid the noise of Brexit and Covid) decides it wants to impose a heap of costs and bureaucracy on foreign companies to arrange payment of sales tax on every order, no matter how small, then it will be a crap show.
Here in the UK when the change was made,
a) Some companies understood the process and decided to stop shipping to the UK because they couldn't reasonably comply
b) A few online market places (e.g. Aliexpress) actually correctly implemented it
c) Everyone else ignored it and hoped for the best
In practice what seems to happen is for low value orders, sales tax does not get charged, even though it technically should be. JLCPCB I think have now moved to category b) correctly implementing UK sales tax, but it took them 5 months after the change happened and I had some boards shipped anyway with no tax paid (quite wrongly)
I don't mind paying tax but no company should be expected to collect foreign goverments tax on their behalf and do paperwork and pay extra for the privilege. Which is the UK gov current position.
The EU are doing the same thing from 1 Jul I think, but a) They are the EU and a massive market b) It is fully automated and transparent *within* the EU.
Smaller countries like GB and AU doing this makes no sense and will just piss off retailers.