Do you have a source on the last part? The rav4 EV has an aggressive regen mode, it's just not the default state of the 'transmission'.
Toyota’s rejection of Tesla’s proprietary regenerative braking system, as it enabled the system upon release of the accelerator which Toyota felt was too abrupt and disconcerting for their customers. Any adjustment meant opening up and sharing either Tesla or Toyota’s “code” – of which neither was willing to do