Do not assume that you will get the speeds the operators advertise in their advertisements.
Fixed Internet service providers (ISPs) have to mention the minimum, maximum and generally available speeds in their contracts and on their websites as well.
A BIPT Decision defines how these values have to be interpreted concretely, taking into account the set-up of networks in Belgium:
The actual speeds shall be between the minimum and maximum speeds and preferably as close as possible to the generally available speed.
Belgium missed two European deadlines for the 5G roll-out in 2020: 30 June 2020, the date set for allowing the use of 5G in the 700 MHz band and 30 December 2020, the deadline for 3400-3800 MHz and at least 1 GHz in the 26 GHz band (provided there is sufficient demand from the market, which is not the case in Belgium today).
Most European countries did make the 5G pioneer bands available: