We use Eufy security cameras for our home, so got an indoor one to use in our daughter’s room as a monitor. It has an app that you download to view, and we can also view it via our Alexa.
Unless you are in a multi-story house and on a different floor than baby, you can probably just hear your baby cry if they need you... When I was in a single story house, I really only needed the monitor when I worked in the garage. Which was about twice ever. I got a free one but really didn't need it...
I used a cheaper indoor security camera.. it was like $40 for 2 & it connected to my phone. Never had issues!
I have a nanit and love it