It’s about 0.6% COVID versus 0.1% seasonal influenza in the US. However, note that the latter figure is the IFR for the “typical” flu. The sentence quoted notes “all other flu-like viruses” - of which there are varieties that are less and more dangerous. Given that qualifier, the quoted sentence doesn’t seem obviously false to me.
[1] https://www.sciencedirect.com/science/article/pii/S120197122...