In the United States, if one wants to take advantage of myriad adjustments ("deductions" and "credits") that the Internal Revenue Code makes available, one typically uses a tax software program. I believe there are four such programs available to consumers (Turbotax, Tax Act, H&R Block, and Tax Slayer). (There are "professional" versions of each available to accountants.) At least one of these programs, Turbotax, is available as SaaS, but, if you have complicated taxes (e.g., partnership interests with annual adjustments to basis), the SaaS version of TurboTax does not give access to all the requisite tax form fields.
Therefore, many of us end up using desktop software to file taxes and pay around $100 for it every year. This software runs only on Mac and Windows (and now only on Windows 11!). I managed to get Windows 11 installed on my unsupported 2015 Dell XPS13 and file my taxes. I don't like running tax software on my Mac, which is for BACCH only, and I don't have any other non-Linux machines in the house.