As someone else said, there is no free lunch. I found that most folks that long ditm calls were retail folks like us and our counter parties were market makers. I don't expect them to lose $ so somehow we are paying for it. Notice the IV of ditm are usually very high, sometimes 2x ATM. and then there is bid ask spread that will cost you dearly. The market is quite efficient and option pricing theory is well known so all the advantages/disadvantages are priced in. I did back testing on spy and yes, I got higher returns but also higher volatility (CAPM) so in down years the simulation did worse than the underlying. in fact you don't need simulation or CAPM to see that leverage will increase your risk so risk/return has no advantage. if you are willing to go long term your return will likely be higher than the underlying but you will have big whipsaw returns. Notice if you buy small caps and stay long term the returns will likely be better. So you say OK in a down year you are no worse than holding the stocks because the rest of your $ is in risk free funds but don't forget if you only invest xx% in option and keep the rest in risk free $ your overall returns will be down because your returns on risk free is poor. To achieve better return, you have to go all in and in 2008 you would be wiped out. I don't know if I am making any sense? That said there are ways to make it comes out positive but I have not found any foolproof ways yet. Regards.
In my opion, deep ITM options have the same risk as owning the stock, but less liquidity, is subject to changes in IV, suffers time decay, and has large spreads. If you want a delta of 1 why not buy 2 ATM calls? Theta will be greater, but you will have less risk in a rapid move against you due to gamma.
Instead, buy the stock and buy the out of the money put. You get all the perks of stock ownership and the protection on the downside. You also pay less in bid/offer and have more liquidity if you really need it. You will get more relief from the broker as well. A $1 strike SPY call requires more margin than SPY shares even though the risks are almost exactly the same because options are not marginable in reg-t.
better strategy might be to purchase out of the money call bull spreads instead of buying deep in the money calls.