A command like listforwards

[fiatjaf]

Does Eclair keep track of forward attempts and successes?

If yes, would be great to have a command to list those.

If not, maybe just a command to display how many channel updates a channel had. I guess this already exists.

[fiatjaf]

This command shows the number of HTLCs that have been attempted I suppose: eclair channels | jq '.[].data.commitments | {remoteNextHtlcId, localNextHtlcId}'

But there is probably more that can be inferred from the channels data that I'm missing, right?

[t-bast]

Have you tried the audit API (https://acinq.github.io/eclair/#audit) and the channelstats API (https://acinq.github.io/eclair/#channelstats)?
You can also directly read from the audit database, but it may be a bit more work to decode the content (IIRC with postgres you have everything in json format, but not with sqlite).