I wonder how much longer the iPod Touch will stay. I think 2022 will be the year of the great culling of Apple's mobile line for new features.
Apple released the current iPod Touch when people where saying they would completely stop creating iPods. I think they will keep updating the iPod touch every few years (so I see a "new" iPod touch next year (same design, new SoC) or maybe even an upgraded one with OLED display)
On topic; I don't really care for the 3.5mm jack. Most devices don't have a good internal DAC, so even if I use my headphones wired I use an external DAC that connects over USB-C or lighting.