Yes, the lossless audio file you're using is probably compressed — that's completely fine for this reason.
A detailed industry explainer is challenging common misconceptions about 'lossless' audio, clarifying that many lossless formats are compressed yet retain full fidelity. The report distinguishes ...
How lossless data compression can reduce memory and power requirements. How ZeroPoint’s compression technology differs from the competition. One can never have enough memory, and one way to get more ...