Defi and NFTs will not only be important elements in the cryptospace, I reckon Defi will be the main element that will serve as basic infrastructure for all digital items created in the cryptospace. This will include NFTs as mentioned and will also serve cryptocoins like Bitcoin, Ethereum, other altcoins and stablecoins. Defi can also serve casinos, DAOs and many other usecases.
Before I had a wider understanding about Defi, I thought it was only another new scam in the cryptospace that will be forgotten. This is because I thought Defi would try to serve real world assets of value that will be tokenized. I was clearly very wrong in this type of thinking. It was when I was beginning to witness the longterm cultural value of NFTs when I realized of Defi's importance as an infrastructure for anything with value in the cryptospace.
In any case, there are Defi projects in the cryptospace already serving NFTs to provide liquidity for them. I speculate they will be the next 10x - 100x projects.
DeFi and NFTs will do well but you are forgetting a lot of other usecases like digital identity, remittance/payments, metaverse, gamefi etc. What you could do when investing, instead of trying to guess the next sector that pumps, is invest in L1s that these topics are going to be build on. ETH itself is not capable of hosting all of these future DApps because of gas fees but projects like HBAR and ICP that are infinitely scalable are. Consider that! We have an opportunity to invest in something like the internet before the standard is created. Why limit yourself to just investing in one website when you could own a piece of the internet- that's an analogy.