There are no iPhone itemized repairs, with most items resulting in an equipment swap. Some of these are subsidized (for instance, some battery replacements). The replaced items are salvaged.
Linus's numbers are sensationalized on top of that - he drops the equipment return and salvage credit at some point, considers equipment rental as part of the part cost, as well as running numbers for his person's time (who I'm not sure is a trained technician, just that they value their time more than minimum wage). I personally would have looked for an AASP source for a cost comparison.
Mac numbers will lend themselves quite a bit more to an apples-to-apples comparison.
Repair shops have only been able to compete on pricing when they use non-OEM replacement parts or repair the OEM parts. Both these approaches are both getting much more difficult.
Independent repair shops also have the sales disadvantage when they don't have a relationship set up to cover warranty repairs - so they often would be quoting OEM replacement parts for gear with years of depreciation, as well as upgrade benefits when the customer does a cost analysis.
I'll go so far as to say if a repair place _ever_ quotes a cheaper price on a repair than Apple does themselves, they are doing a different repair. They are repairing the OEM part rather than replacing it, they are replacing a OEM part with a part salvaged from another device, or they are putting non-OEM parts in. For screen and battery replacements, the majority of phone repairs, it's almost always non-OEM parts.
Apple testified to Congress that their repair services lose them money [1]. If they have not focused on their own repair services profitability, then they likely also have not focused on profitability of independent repair services.
1: https://docs.house.gov/meetings/JU/JU05/20190716/109793/HHRG... , response 21