I didn't actually watch this particular 'this old house video', but there are countless similar vids on YT. A manual transfer switch is absolutely the way to go. Depending on how handy you are, and how much you want to power, with a little DIY savvy, you can have the ability to run critical circuits in your home during outages for well under a $1000. Whereas a permanent whole home generator will cost several thousand or more, and wont be available to take on camping trips etc.
I live outside of city limits. So widespread power outages put us at the bottom of the priority list. I have a 5000 Watt portable generac generator that runs all my essentials. Furnace, water heater, refrigerator, 1 bathroom, well pump, sump, septic aerator, Dish, Starlink, etc. My system can power 6 circuits, but they sell larger and smaller transfer switches than that.