Because the Thunderbolt interface is patented by Apple, promoting it is equivalent to restricting the USB3.1 ecology mainly promoted by Intel, so it is difficult to see it in Intel notebooks other than Apple. Instead, it is used by some third parties. Shenma's headphone monitor and mobile hard drive have more support. Anyway, if people use Apple's interface, they will pay Apple a share of the patent fees and earn a share of Apple users' money. Intel is not happy and cannot bite them. They have to persuade them. Third-party Duoduo supports its own USB3.1 and future follow-up products.
As for the MXM interface, this is the patent of NV Lao Huang’s family. It was not popular when it was launched in the early years - low-end machines can’t afford the extra patent fee and the additional interface components. High-end machines can’t afford it. Computer users don't have any objections to the whole replacement of laptops, so they don't need it. Moreover, Intel and AMD don't want to add an additional NV to their laptop platforms to collect patent fees, and they are restricting its development overtly or covertly. NV itself actually hopes that notebooks can be replaced more than upgraded, so they don’t bother to promote this technology. Alienware and barebones use this interface more. In recent years, even Alienware has gradually begun to use this interface. I gave up on this set and only kept it in a very small number of high-end configurations - however, it is basically impossible to buy MXM notebook graphics cards on the market, and it is basically a dead market.