Yes. Without a doubt.

I worked with a QA team for the last fifteen years until last year when they laid them all off.

QA is a discrete skill in and of itself. I have never met a dev truly qualified to do QA. If you don't think this you have never worked with a good QA person. A good QA persons super power is finding weird broken interactions between features and layers where they meet. Things you would never think of in a million years. Any dingbat can test input validation, but it takes a truly talented person to ask "what if I did X in one tab, Y in another, and then Z, all with this exact timing so events overlap". I have been truly stunned at some of the issues QA has found in the past.

As for time, they saved us so much time! Unless your goal is to not test at all and push slop, they are taking so much work off your plate!

Beyond feature testing, when a customer defect would come in they would use their expertise to validate it, reproduce it, document the parameters and boundaries of the issue before it ever got passed on to dev. Now all that work is on us.