This is a faulty argument. Regardless of the encoding, MP3, MQA, WAV, FLAC...all of these files are proprietary. You can't legally give one of your Spotify files to someone who doesn't have a Spotify subscription can you? All of the companies are trying to make a profit aren't they? Spotify has a proprietary connection format they offer to hardware manufacturers, don't they? So does Apple, Amazon...the list goes on. I fail to see how providing consumers with more options ruins anything.
To the OP. You can stick with your Tidal subscription if you like. If you don't use or care for their proprietary MQA format, you still have their lossless streaming for $10 a month. I would start there and compare their library, UI etc to other players in the market. You can't go wrong with Spotify. They're adding lossless and they have a good UI. Spotify is very good for parties (shared play lists etc.). The beauty of the subscription is that you can change it later and go with a different provider. You're not locked in.
{edit} I wonder of Spotify would be offering lossless streaming if the weren't pushed to do so by their competitors (Tidal and the evil MQA empire)