Based on what you've got and where you're going, I think teh EOS 90D would be a great upgrade. The Dual Pixel autofocus will allow for sharp movies even when the camera or subject are moving and its still relatively small compared to the EOS 5D series so it won't stand out as much while shooting street photography. The EOS 90D can also use your current EF-S lenses as well as EF lenses. Like most of the new EOS cameras, the EOS 90D also has a WiFi connection capability so you can use your phone as a remote with live view.
Keep the T3. buy a EF-S 24mm 2.8 STM. Shoot with that for a while. Perfect for street photography and you sure won't find a lighter kit to carry around. Bonus: the EF-S 24mm 2.8 is cheap and exceptionally sharp. Need low light/high ISO, try a 80D. Almost identical to the 90D and a lot cheaper. Even a T7 would be a nice upgrade that won't cost a fortune.
07/31/2023: New firmware updates are available.
05/31/2023: New firmware updates are available.
05/18/2023: New firmware updates are available.
04/20/2023: New firmware version 1.4.1 is available for EOS R3
03/30/2023: New firmware updates are available.
2/07/2023: New product announcements!EOS R8 EOS R50RF-S55-210mm F5-7.1 IS STMRF24-50mm F4.5-6.3 IS STMRF15-30mm F4.5-6.3 IS STM