Thats a really good point regarding EU citizens having access to this service. Swedish services are thoroughly tied to the bankid/personnal number. There is a EU regulation [1] somewhat related to this that prevent sellers from discriminating the availability of goods based on your place of residence.

I wonder if this regulation applies to these shops.

A couple of paragraphs are particularly interesting, #18 and #19:

(18) [...] traders should not, through the use of technological measures or otherwise, prevent customers from having full and equal access to online interfaces, including in the form of mobile applications, based on their nationality, place of residence or place of establishment. [...]

(19) In order to ensure the equal treatment of customers and to avoid discrimination, as required by this Regulation, traders should not design their online interface, or apply technological means, in a way that would, in practice, not allow customers from other Member States to easily complete their orders.

[1] https://eur-lex.europa.eu/legal-content/EN/TXT/?qid=15422088...