As some have mentioned, the only way I can see a lot of investors considering it is one of two ways. The first being stablecoins.
BUT, I don't see them wanting to use "over collateralize" tokens like DAI or EOSDT, simply because to most people, it won't seem much different from regular crypto.
The ones that people will most consider are USDC, BUSD, and GUSD. Why? Because the big companies associated with them--Coinbase -> USDC, Binance -> BUSD, and Gemini -> GUSD, each pledge a 1:1 exchange between their stablecoin and the USD. I've heard TUSD via Trust are 1:1, but my initial research has been inconclusive.
The other option is to use a 3rd party service, like CoinPayments. They allow you, in their options to receive payments, to autoconvert. This allows you to accept a wide array of crypto, and you can then choose to autoconvert to the stable coin of your choice. They do have an integration with Coin Base, to make USDC the easiest choice, but they do include BUSD, GUSD, and TUSD.
NOTE: Unless you are willing to use another exchange to transfer between USDT (Tether) and others, I would say not to use it. On their site, they won't convert to USD, unless you have several (hundred?) thousand dollars to convert. That means that your only option is to either convert to fiat via P2P (and hope to get a good price), or on a central or decentralized exchange, with similar issues. Better off with one of the above.
The advantages of accepting crypto--either stable, or via auto convert--is that you can receive your money in hours, instead of days/weeks, without worrying about "bankers hours." Want money on the weekend, or holidays? It can be done.
Another thing is the fees. Generally, when you look at fees charged by credit card companies, debit cards, prepays, etc, the fees on crypto (stables) are generally considered lower. Note that I'm not sure how much the Ethereum (where many of the stable coins are based) gas prices (cost of doing the transaction) play. But for that issue, many of the stablecoins have equivlants on Binance Smart Chain, and Polygon.
Lastly, depending on where you look, you can earn an average of 8% APY on your stablecoins (some more, some less). The highest I've ever heard to earn on USD, via some credit unions, is 5%.
It will take some learning, and for a lot of people, it's not something they'll want to deal with. You would have to sit down with each of them, and present a lot of what I just laid out, to begin. But, if you can, I see a lot of possibilities.