The barriers are becoming more difficult. Some factory PCMs are so tamper resistant that the aftermarket just sells replacement PCMs that are easier to retune rather than hack tough OEM software. The OEMs emply a lot mord engineers and can afford much more R&D than the aftermarket companies who have much smaller budgets. It doesn't help that car owhers don't own the software in their cars, they only have an end user agreement. The software is still completely the property of the OEM and there they remain a co owner of your computer controlled car. Evenmif you swap the OEM ECM out for aftermarket OEM, that manufacturer also owns the software, not the purchaser.
The biggest issuse facing hotrodding in the future for both ICE and EVs is increasing in car surveillance that is being built deep into modern cars. Teslas are well known about collecting and recording data on their drivers and sendingbit back to HQ, GM Onstar also spies on car occupants and other manufacturers are getting in on the act. If you start to monkey with such cars they will rat you out to the OEMs as they remotely monitor car now, possible LE in the near future.