@Scott Trench Adding to your views on crypto, I'd suggest Web3 and DeFi as reasons to invest in the asset class. Personally, and as an Investment Advisor, I stick to various index funds over individual stocks due to the risk and historical performance between passive indexing and active trading. However, in crypto you could assume that a blockchain that supports Web3, DeFi, and is an industry disruptor would be a viable investment for a small allocation of your portfolio. I'd rather take the volatility and speculation with one crypto over one stock. An example that comes to mind is the Helium blockchain, although there are several more projects that fit that criteria.
The only category I think your missing is leverage. I believe this is a common category people don't consider when investing. As we know in REI, you can use HELOCs and Cash Out Refi's to access cash (at a cost) to do more deals. Well we can do nearly the exact same thing in our Individual or Joint Taxable accounts. We can continue to invest (ideally dollar cost averaging into Index funds) in those accounts, then utilize a Margin Loan (sometimes called line of credit) to access cash at an even lower rate then HELOCs or hard money lenders can offer. I recently completed an ADU Airbnb renovation just using my Margin Loan at 2% interest, without having to sell any of my ETFs. Good examples of brokerages that offer low cost Margin Loans are Interactive Brokers and M1 Finance.
You might call this a self-lending strategy. This allows us to build our portfolio, increase our leverage, then utilize that leverage on a rental property for example. It's all about preparing our finances and purchasing power for the next deal!