The .eu TLD signals EU-wide regulatory scope under MiCA (Markets in Crypto-Assets Regulation, in force 2024). For Bitcoin products operating with EU-passportable licensing across multiple member states, .eu is the natural anchor — single license, single brand identity, 27 markets.
.eu is the one extension that says single market without naming a country. For a Bitcoin business operating under MiCA across several member states it avoids the awkward choice of which national domain belongs on the invoice.
Registration is restricted to residents and entities of the European Union, which keeps the space smaller and cleaner than the open generics — a side effect that works in a buyer's favour.