It's true that I've not used my coverstitch half as much while I've been covid sewing but, when I do, I use the chainstitch almost as much as the main coverstitch - sometimes more.
I use it for basting a lot, especially for knits as it has some stretch - as much as a zigzag which I used to do to try on dancewear until I decided I preferred to overlock & zigzag once I'd got the hang. If I want to add a bias binding finish to a stable knit I use it to attach the binding (neater and less bulky than overlocking) and sometimes choose it for a self bound edge if the fabric has bulk. If I want a bold single line top-stitch it's great for that too using the reverse side and moving the needle position to the required distance away from the foot edge to achieve an accurate width. My machine Bernina L220 (Juki made, twin of the Juki MCS -1500) performs well sewing chainstitch in any of the needle positions.
It's a very strong and robust stitch and if you're really bothered about it coming undone when you want it to be permanent, knot it and add a blob of fray check or such to the knot. I keep finding extra things that it's useful for. It's now my standard stitch for seaming net skirts after noticing it was used in a vintage dress. It's so secure and strong without the puckering that a sewing machine can create and remarkably invisible despite its thickness. I can press the seams open to make them even less obvious too.
I have the specialist chainstitch presser foot but never feel I actually need it and forget more times than I remember.