Framework shipped AMD 7040-series and 13th-gen Core i-series alongside each other for the 13.
The 13th-gen Intels had miserable battery life and heat issues under load. If you could manage that, all four USB-C ports were full Thunderbolt ports equally capable of driving displays, PD, and USB 4 throughput.
The AMD line had considerably better performance-per-watt but rougher firmware support (and early on, really broken Linux kernel support that required Fedora or other rolling kernel release distros). It also couldn't deliver the same "every port does everything" promise that the Intel boards did, with some ports not supporting displays or USB 4, which significantly reduced the value of the expansion-card model to kind of a novelty.
On the 12, if it's likely also going to have a smaller batter than the 13, going only with 13th-gen Intels means it likely will be either a further step back in battery life vs. the 13 or throttled to extend the battery.
The issue isn't TDP so much as performance-per-watt. The equivalent Ryzen 5 PRO 7540U can run at the same base TDP, had 2 full and four 4c cores on a smaller die, and outperformed the 1334U almost across the board.
Both chips were Q1 '23, so the timing's not a great excuse. They were in HP's 2023 EliteBook G10 840 (1334U) and 845 (Ryzen 5 PRO 7540) laptops, and the 845 was better on both single- and especially multi-thread Cinebench R23, _much_ better in GPU loads and gaming, _and also_ lasted longer on battery.
I think Framework mostly just wants to target an education market with a mainboard experience that's lower maintenance than AMD has been for them. Fewer USB-C restrictions, less firmware drama.
Still hard to get excited about it being the _only_ available option, though.
I would suppose they got a good deal on them, as they're a little out of date, but they're good enough, and overall provide a good package. If you're trying to hit a price point, there will always be compromises.
The 13th-gen Intels had miserable battery life and heat issues under load. If you could manage that, all four USB-C ports were full Thunderbolt ports equally capable of driving displays, PD, and USB 4 throughput.
The AMD line had considerably better performance-per-watt but rougher firmware support (and early on, really broken Linux kernel support that required Fedora or other rolling kernel release distros). It also couldn't deliver the same "every port does everything" promise that the Intel boards did, with some ports not supporting displays or USB 4, which significantly reduced the value of the expansion-card model to kind of a novelty.
On the 12, if it's likely also going to have a smaller batter than the 13, going only with 13th-gen Intels means it likely will be either a further step back in battery life vs. the 13 or throttled to extend the battery.