the biggest reason back then was that it had the best charging network option. as NACS slowly becomes the defacto connector standard, the unique factors that teslas have starts to yo dwindle.
in pure EV though the alternatives arent entirely less expensive. its a game of certain features over others. For example with traditional car conpanies, many of them still have a terrible cartainment system, with some threatening for example to take away apple carplay/android auto im favor of their own propoetary service.