A lot of people wonder if Standard Shopping and Performance Max compete with each other.
They don't, they complement each other.
Standard Shopping captures high-intent searches and builds up real conversion data. PMax then uses that data to make smarter decisions across all of Google's channels.
Without Shopping running alongside it, PMax is essentially guessing. With it, Google's AI has something solid to learn from.
The screenshot above is a good example of what stable, consistent performance looks like when both campaigns are working in sync, 109 conversions, £6.13K conv. value, on just £772 spend.
Don't turn off Shopping just because you're running PMax. It's doing more work than you think.