I agree with you for the most part, but also do disagree. It's complicated. Like water consumption is absolutely far more efficient 10 to 100 times less water used per plant depending on the setup between outdoor to indoor hydroponics. The climate control factor is also a big plus. Sudden heat waves or cold snaps are not as big of a concern with indoor farming. Some places, protection from hail is a huge factor. Even just smoothing out the edges of harsh weather is a huge benefit. These are the tried, true, real world benefits that are both proven and economically efficient already in some small scale vertical farms along with large scale traditional farming plus with hydroponic farming. This doesn't even mention the year round, local supply of certain foods.
However, the electricity issue is the obvious problem along with the artificial light itself. The lights themselves to properly grow plants are not cheap and I saw a study that on an industrial scale, they're also not that reliable (lots of replacements). I have my doubts about the long term nutritional factor of using artificial light. We are evolutionary developed for plants that process the sun for their different forms of photosynthesis. I'd trust plants raised on the light of a fusion reactor more (tongue in cheek, chill). I did read something where researchers are trying to breed certain crops to respond better to artificial light, but I don't know at what stage they're at with it.
Wind energy is still not 100% reliable for obvious reasons and there's only a ~20% efficiency of solar right now on the commercial market (unless something has happened I don't know about). If you're aware of the conversation of energy, I doubt I need to really go into more of that. However, it's a good extra step forward for further market investment in renewables with essentially an extra market to purchase said products (still a win-win).
Without being a party pooper, I still see vertical farming as having potential. All crops? Probably not, to be honest and serious. 25% at least of produce that's available in your average market? Absolutely. We're just not there yet to achieve that, but you have to start someone to work out the "at-scale" and commercial viability issues. This is all good steps forward as long as you see it as such. If you think it more than that, then you're going to get disappointed and miss the lessons that can be learned.
Beating that dead horse, there are plenty of problems that need to be addressed. Plantagon comes to mind as to their failures, but that was a bit more money related due to not realizing the infrastructure requirements (plus, from the articles I read, I smell a bit of... corruption? con-artist? bullshit?). Respecting the problems at hand and trying to fix them is far better than just going, "We need to change everything to vertical farming now! You're a piece of shit if you think otherwise!" Which is kind of where a lot of these conversations and articles go. None of which is beneficial for anyone.
You're idea of investing in Africa is generally the tried and true commercial agricultural method of expanding food supplies. Nothing wrong with it, as long as you don't go Belgium's King Leopold II about it. But I'm not 100% against diversifying food supplies at some sacrifice to efficiency both short and long range in time and distance. I think the pandemic shows how important it is to never have "one source" of anything. The logistics dangers never show up in the good times, but they can make the bad times really bad. I like the vertical farm idea due to the decentralized concept.
There's pros and cons to the vertical farming movement. I don't believe we're at a point where a major portion of the food supply can come from it. I really think a decent portion (20%-30%) can come from it within the end of the 2020s with better economic efficiency than traditional farming. Beyond that, no one can really predict it without their personal biases playing a factor. Once we can shut up the fanboys and wannabe environmentalists who have bullshit degrees in nothing actually useful from spouting stupidity and diverting investments to con-artists, real progress can be made and some benefits can be seen relatively quickly. I want to double down on that statement, the over hype and fanboys do nothing good for any technology. Their rhetoric diverts investments from those who make real progress in a field to con-artist ponzi scheming assholes. The more emotionally charged something is, the more this happens.