When it comes to FLAC vs WAV, I have to say that both FLAC and WAV have their own strong and weak points. A WAV file is significantly larger than an equivalent file in FLAC format since the former one isn't compressed. To make it clear, sometimes a WAV file is longer than FLAC because WAV cannot recognize the period of salience while FLAC can. Besides, the FLAC format uses sophisticated and advanced techniques to pack and unpack audio, thereby reducing the file size, making it suitable for online distribution or storing on local hard drives.
As for the compatibility of these two audio formats, WAV format is supported by more devices. WAV is widely used in many devices. However, WAV has no metadata tag information while FLAC does. Therefore, if you want to embed some information like track number, album cover, lyrics, etc. in your file, FLAC is more suitable for it.