I use Wise regularly and pay about 0.5% for EUR/GBP/CHF transactions.
The reason why DeFi exchanges offer low fees is that they are not “companies”, they are fully automated and have no overhead. For a company offering forex services the main expense are salaries, not fees (that on wholesale markets are on the order of 0.01%), therefore they would not benefit from using a blockchain as an underlying layer.
And completely unrealistic in Zurich. Unless the price refers to a 1-room apartment (which in US English would be a studio, in Switzerland typically all rooms are counted for apt descriptions, a 1-bedroom apt is called a 2- or 2.5-rooms apt)