If weedkiller was the be all and end all, then I doubt very much whether we would have weeds at all any more, after the 70s and 80s.
People at our allotments spray as often as I weed. All you get with weedkiller is stronger weeds as the ones it doesn't kill have more space to grow. Some of the weediest plots are the ones where they spray intermittently because they think if they spray, they don't have to weed. Doesn't work like that!
One sprays relentlessly and his patch is immaculate. So immaculate it is sterile. when you go past mine, there are birds, insects buzzing, frogs and toads hiding under bricks and little houses I leave for them, frogspawn in things I leave out to catch the water and it is a haven of activity. Go onto his, and nothing. Just grass, soil and perfectly positioned veg. The soil isn't dark and full of life either, it is almost grey.
Couch grass, once composted, makes lovely loamy compost.
If you are a gardener, you will always have weeds, as long as you have soil. you just have to get used to that fact.
Dandelions are good for the bees, what I do and what has drastically reduced the numbers is, leave them to flower and once the clocks turn, I have a hand held rechargeable vacuum, and I hoover the clocks into the vacuum and then put that in the bin. Then they eventually get dug out and composted.
Chits - you don't have to chit potatoes, people put them in light to keep the chits small, rather than leaving them in the dark where they grow long and take energy from the potato. I used to put all mine in on 17th March, but with the seasons, I am now putting them in at least a month later. Less work keeping them frost free and like most plants, they catch up the earlier planted ones that often react to frost by slowing down.