The best alternatives to Matrix Powerwatch are Pebble Time, Moto G7 Power, and Waterpebble. If these 3 options don't work for you, we've listed a few more alternatives below.
The Moto G7 Power is packing a Qualcomm Snapdragon 632 processor with 3GB of RAM. It comes with just 32GB of storage, of which 18GB is available out of the box. Fortunately, you can add up to an additional 512GB of external storage with a microSD card.