Intel is the worlds largest chip-marker. They primarily make computer CPUs with high-clockspeed and low core-count. This makes their chips very attractive for applications that require high single-core performance.
e-mail addresses from @intel.com have been a very frequent occurrence on the Linux Kernel Mailing List since the early 2000s. They are, and has long been, one of the largest corporate contributors to the Linux kernel. Intel is also making regular contributions to the Mesa graphics stack.
Intel did have some screw-ups with their i915 graphics driver for their GPUs between Linux kernel 5.3 and 5.5 which makes their iGPUs essentially unusable in 5.3.x and 5.4.x series kernels. Most of these issuers seem to be resolved as of 5.5rc4.
Intel is all-in-all one of the overall most free software friendly hardware manufacturers.
Intel is a large manufacturer of networking equipment. Their cheaper networking chips are found on higher-end consumer motherboards and their high-end network chips are frequently found on enterprise-level network cards. Older enterprise-level networking cards with Intel network chips, such as the quad gigabit HP NC364T, are readily available in the used market. Such cards are typically very well supported by the Linux kernel.
Wireless consumer network cards from Intel will typically work as they should right out of the box on GNU/Linux systems. Intel has long had the best free software kernel driver for wireless networking.
Bugs in the system
Intel CPUs have been plagued with a very high number of serious CPU bugs which require a lot of software workarounds. It is possible to disable many of the Linux kernel workarounds for Intel CPU bugs. Doing so is not advisable but quite possible for those who value pure performance over security.
Intel's the #1 chip-marker
Intel was the number one chip-marker for a decade before being knocked down by Samsung in 2017. Intel regained the #1 spot in 2019.