It isn't a hobby of the past. Arborists are professionals still using knots and studying them (especially with the modern rope materials changing the old knowledge around knots). Rock climbing is a hobby but knots are life-or-death for them.

Knots are still being invented nowadays. Or variants of existing knots.

Here are PACI's systematic studies on a few vital knots:

https://www.paci.com.au/knots.php

Here is a recent (2025) paper on the stability of the bowline:

https://www.epfl.ch/labs/flexlab/wp-content/uploads/2025/11/...