Sell me on this coin. I have been an investor since nearly the beginning and all I have seen is wallet failures, delays, and features that have yet to be implemented. Why should I stay invested? Or, why should I invest more?

Nobody needs or wants you. Anybody buying XCR right now are simply transferring coins from one person to another. The devs only needed the 750 btc ipo funds to move the Crypti project along. They raised it in the ipo in exchange for coin distribution.
If you believe in this project then those of use who own XCR are privileged to be a part of history that crypto currencies in general will play years from now. A speculative bet on XCR now can possibly net you a fortune should Crypti achieve what it sets out to do.
Anybody who demands timelines, updates and made up promises they injected in their own brain are lost and needs to hold their mommy's hand the next time they ride the bus. Do
you really think the devs who created everything you've "invested" in need you to remind them of things?
There is nobody in the world who wants to deliver all the features more than them. But they will do it when it is ready and not a day sooner. If you don't like it then volunteer your programming skills to help move it along instead of making false accusations of broken promises. Otherwise, sit back and enjoy the ride. This thing is either going to make bitcoin millionaires jealous of me or fizzle and die. Either way it was worth putting as much as I can afford to lose.