Having started companies in Norway without being rich at the time, it's not generally remotely a problem. The wealth tax is low, and it only kicks in over a threshold. If you can't afford to have your company pay you enough or lend you money to cover the wealth tax at the point where it starts to become a challenge, then your company is likely a shitty investment.

There can be extreme corner cases where it's a challenge, but it's extremely rare.