When a 5 sat/b could have got you into the next block for like 90% of the time during the last month, I doubt it's because of the fees.
Perhaps, though it is quite important to note that there are better alternatives as well. Fees almost always spike during bull runs, at least from previous experiences. I've no doubt that some of them are more reluctant to keep it out of their exchanges, you'll probably either miss the opportunity or pay a ton of fees.
Speaking about fees, I know LN has been experiencing quite a growth since then while having far lower fees. Might be a factor as well.