Ethereum and DeFi are the great example of high transaction fees. I'm 100% sure, that after DeFi rans out of hype power and becomes something regular (like ICO and IEO now), people will come up with something new, that will grow an interest to bitcoin. And where is interest, there are people who will want to earn on it. You dont need to go far for an example. Every time bitcoin's price grows speedily, network fees goes up also.