I empathize. When my twins were that age, I barely had time to breathe, never mind cook.
The advice that annoyed me most was “give them what you’re eating”. I had a chicken Caesar salad for dinner 6 nights a week, since I was too exhausted and had no time to think of anything else to cook. My 8-month olds didn’t want a salad.
I used to batch cook for the kids - bolognese, lamb and lentil stew, etc. And batch cook butternut squash, carrots, parsnip, sweet corn, peas, broccoli, peppers, etc, so there was always a pot of something in the freezer and I just had to add potato/rice/pasta.
They had porridge and fruit for breakfast, batch-cooked hot lunch, and the same picnic dinner every day (selection of things from toast, eggs, hummus, olives, cherry tomatoes, avocado, cucumber, cheese, cold meats, smoked salmon, tuna, etc). They ate way healthier than me.
Now age 6, they eat most things but hate most vegetables (even though they loved all vegs as toddlers).
I recommend the Joe Wicks “Wean in 15” book for lovely kids recipes if you’ve the time to cook them.