Flexbox has been useful, but for me has essentially been superseded by css grid, pretty much for the reasons you mention. I find flexbox to be difficult to use

Flexbox has been useful, but for me has essentially been superseded by css grid, pretty much for the reasons you mention. I find flexbox to be difficult to use and feels more like a stopgap feature on the way to full blown grids than anything long lasting. I wish subgrids would become standard, but regardless we're in a much better place these days vis-à-vis css layouts than we were pre-grid.