When trading between EU countries, although you have to calculate and charge VAT based on the location of your consumer customers, if your business only does a small amount[1] of goods trade with various EU countries, or if it's supplying services[2], or if it's supplying online services[3], or if it's supplying goods or services to other businesses[4], it isn't necessary to have a company presence in each individual country.

So for businesses expanding into new EU countries it's not as onerous as needing a local presence would be.

(Disclaimer: I'm not an accountant and may be wrong. I'll take it on the chin if so. This is just my understanding, having needed to look this stuff up occasionally.)

[1] https://europa.eu/youreurope/business/taxation/vat/cross-bor...

[2] https://europa.eu/youreurope/business/taxation/vat/cross-bor...

[3] https://europa.eu/youreurope/business/taxation/vat/vat-digit...

[4] https://europa.eu/youreurope/business/taxation/vat/cross-bor...