A 3-year-old definitely takes a lot more continuous attention than a newborn (assuming the newborn is healthy, eats and sleeps okay, ...).
I was able to get some amount of work done while taking care of my first kid up to about age 1. In the two years since then, not so much (I just pray for conveniently timed naps). The second one is 6 months old, and is way easier to take care of right now.
If you just accept that you will be doing no independent creative work, then a 2+ year old isn’t too bad. They can start to “help” with routine chores, can walk around for themselves, can feed themselves, eventually stop needing diapers, etc. The work is not really hard per se. More like relentless.