I use WeBull app to track my performance and it has the following way of showing your holdings against your chosen benchmark:
This particular app shows your performance with the blue line and your benchmark with the red.
Because all my stocks are within S&P500 with no exceptions, I chose it to be mine, but there are plenty other options too, including various FTSEs.
Maybe something we could have with Freetrade. Not initially of course, but as part of gradual app improvement 