Large kitchens are much worse than smaller ones for efficiency and work flow.

It ain’t about the size. It’s how it’s used.

I agree and I have a kitchen that is on the large size but designed it to be functional for how we cook and I also run a small catering biz from there so that needed to be considered. 15x 20 is not a huge space . Could you post a floor plan with as much detail as possible , like plumbing, doorways , windows

Mine is 17'x15' if you include the whole room (and has an added pantry that's 8'x10'). However, it has a peninsula that cuts about 4' off one side due to three doorways all being on that side, so the peninsula creates effectively an open passage away from the work flow of the kitchen. It's an old farmhouse, so also has a chimney and antique wood-fired boiler on another wall, so effectively that cuts off another couple of feet, so mine doesn't most likely compare.

As SW said, it's about the layout and how it's used. Unless you want it only as a show piece rather than functional, think about the main work triangle (stove, refrigerator and sink) and keeep the space between them compact enough to reduce steps. Think about work flow such as from sink to dishwasher to dish storage or from refrigerator to sink to stove. Do you have counter space for setting things down and prep space where needed? Do you often have multiple people cooking at the same time? My layout is comfortable for me alone, but also works with another three folks there as I have siblings that enjoy cooking when they visit. This room was pre-existing and it wasn't practical to change the size, only the layout, and the cabinets run across two sides with the peninsula adding about half of a third side. My previous kitchen was far smaller, but still was fine for three folks to work in. So figure out what you want in your kitchen as far as number of cooks, potential eating space, storage, and work areas before deciding on size if you are starting from scratch.