I think the case could be made that in the past several years, WDW received more meaningful additions than DLR did.
Flight of Passage, Tron, Cosmic Rewind, Slinky Dog Dash, Ratatouille, and others, coming in addition to new attractions shared with DLR-whether or not these attractions are the best possible things Disney could have built or fit each person's personal preference, they are nonetheless attractions that are sold as high profile, meaningful additions that conspicuously have no meaningful California counterparts.
WDW also got meaningful infrastructure work with the restructuring of Downtown Disney into Disney Springs, the reconfiguring of the DHS parking entrance, the Skyliner, and reconfigured security entrances with Evolv scanners.
By comparison, there's been very little to crow about with the California-only additions or changes since Cars Land. One could argue that such expansion in Florida was needed to help bolster WDW's capacity issues and/or deal with outdated infrastructure, but DLR got by in the same decade primarily on attractions shared with WDW and frequent entertainment refreshes, while steadfastly clinging to the World's Worst Disney Parks Entry and Infrastructure Experience and thoughtlessly, constantly changing things because they could rather than because they should at DCA. With the entrance gate switchouts, DTD refreshes, and DLForward, it seems like change is finally coming for DLR in the near future, but I can absolutely buy someone looking at the past decade and coming to the conclusion that DLR, while better taken care of in many ways, got the short straw when it came to investments and changes over the past 5-10 years.