You don't buy the best flight tickets on comparison portals. Additional fees are also often required for luggage and seating.
A Lufthansa direct flight to Mallorca for May 2024 (as of January 2024) costs 355.98 euros on opodo.de without Prime membership. Neither seat nor luggage is included. Here you currently only pay 261 euros for the same services: no hand luggage, no seat reservation or seat reservation. The best 3 online travel agencies are fluege.de, flug.check24.de and airline-direct.de.