From what I can glean from reading stuff about it, the SOP breeds will, sometimes, lose production because of not breeding for production. Taking a long time to reach POL and adding meat at a good rate is less important than looking good.
A lot of Hatchery breeds have been crossed with leghorns so they lay well and fast but do not get big so are hard to get up to good meat production.
It seems like some do have good production and are moving up into the SOP Spectrum. Horstman has Kittle RIRs that are good egg layers and the grow fairly fast.
Still the Pita Pintas from Spain and The EO Marraduna Basque have many breeds beaten for both.