Tesla is of course doing better than the other two and have been steadily improving since 2016. I don't have info for the other manufacturers yet. I don't subscribe to it, but go through the archived data which is free.
This trumps any data from CR as far as I'm concerned. It doesn't need to be granular. It tells me that Teslas haven't gotten any more problematic in general over the years, and instead have improved.
Warranty Week uses direct reported OEM financial data. Their reports really are not shaded, IME,and I've been using their products since before Tesla existed. However:
1. Warranty accruals are highest for new products because the actuarial have no basis to establish future claims so the are VERY conservative. As a model ages and becomes more easily assessed by actuaries the accruals become more accurate and nearly always lower. That caused over-accruals for Tesla and continues to do so today as models change with new technologies and new factories plus unprecedented growth. Actuaries hate, HATE, unpredcability.
2. Totally separately, warranty accruals are established as a reserve upon vehicle or other product delivery. IN high growth the reserves almost always grow much faster than do claims because the warranty reserves cover the entire warranty period.
3. When adjusted to link fleet age with claims against reserves (this is very difficult because the detailed tracking data is rarely available for any product) it seems quite likely that Tesla still has much mower claims than do other automotive companies. (All my data on this is proprietary so I will not share it). If my information is correct there are three primary reasons why Tesla warranty cost remains lower than do other automotive OEMs: First, Tesla OTA do address actual problem areas, enhanced durability data and improved operational reliability. Further, OTA can be and is used to make what would be repairs for other OEM. Second, Tesla vehicle reliability has steadily improved with time. Anybody who drone a 2012 Model S and a 2021 Model S understands that nominally the same car has little commonality with the componentes of the new ones. Failures have steadily reduced, thus warranty costs. Third, as Tesla has grown they ahem steadily managed to improve suppliers, designs and quality control so the probability of major defects has dramatically reduced. Fourth, as manufacturing has improved and volumes have increased almost every major process has been enhanced and production volumes grown more precise. In specifics, Front and rear casts of Model Y are reducing parts counts by hundreds. reducing parts reduces failure. Battery packs and all powertrain components are now shared among multiple products. For example, eery Tesla model shares the same operating system, vastly reducing development cost and problem areas. Another example, motors are shared between Tesla models and even SpaceX, improving quality, decreasing manufacturing costs and development costs.
All of that ends out reducing warranty claims to mostly externally produced and supplied parts such as airbags, most screens and myriad other components. The cost fo those warranty claims is normally devolved to the supplier. That does not help the customer with the failure, but it definitely places quality control focus in every failure area.
The remaining serious issue si that the torrid growth rate of Tesla requires commensurate customer service improvements, and those are usually more difficult to accomplish. To the extent that Tesla can continue reducing defects this will be a virtuous cycle.
Now we cope with Airbag replacement on some new vehicles, continuing screen issues and periodic new technology imperfections issues such as the recent Octovalve winter issues. Luckily these are rapidly decreasing number and frequency, which does not provide comfort for the affected by problems.
Sadly for me have had multiple vehicles replaced or repurchased by manufacturers. All four were new technology failures. When two famous German brands were among them and the other two were famed for high quality it is personally obvious to me that there are Lemons! Everyone, including Tesla, can have them.
I regard Tesla as the best of them all. That does not make me less concerned of service, sales and repair weaknesses. On the contrary, it just raises my expectations. In my opinion that is what Tesla is all about.
Now I shall soon order another Tesla.