Actually, I think it might be possible to implement gron in jq (you can produce "plaintext" not just json, and the processing facilities jq offers might be powerful enough to escape everything appropriately, but it's not something I'm curious enough to find out to try).
Practically, most things you'd do with gron and grep, sed, awk, ... you could do using only jq as well. Jq comes with massive cognitive overhead though and has a bunch of very unpleasant gotchas (like silently corrupting numbers with abs > 2^53, although very recent jq graciously no longer does that iff you do no processing on the number).
I find jq pretty useful, but I have no love for it.