I upgraded from 2015 13" Macbook Pro to 2021 14" Macbook Pro, and it's remarkable how similar the devices are. The physical dimensions are almost identical. Neither have a touch bar. And they both have a similar selection of ports (HDMI, SD card, aux, mag safe), and in very similar locations. The difference is basically improvements in quality of pretty much everything: better screen resolution and size, better webcam, better keyboard, better speakers, USB-C instead of thunderbolt ports and USB-A, better battery life, and of course a much much faster processor and thermals.