Legal and tax issues is the main reason. Most companies don't want to deal with them. But that doesn't mean it's impossible. For example companies like Automatt

Legal and tax issues is the main reason. Most companies don't want to deal with them. But that doesn't mean it's impossible. For example companies like Automattic, Convertkit, and Safetywing are fully location independent. Employees can work from anywhere. For the past 6 months I have been trying to develop a home for digital nomads to find location independent jobs. Most remote job boards are filled with remote jobs that restrict working outside the country just like you mentioned. FWIW, I am currently building a paid Discord server to send instant job alerts for location independent jobs. All jobs are hand curated by me to only include the companies that are nomad friendly and care about diversity. If you may find it helpful, consider subscribing. Thanks.