Personally I would spend my money on a phone. The A53 had good overall reviews for value, usability and battery life. I would imagine you will get more out of that than a tablet day to day. But... if you really want media consumption the S6 Lite got good reviews too.
Depends what phone you currently have. You may want to look into how many android and ui updates are left on your current phone vs A53 5g vs S6 Lite. I always find it useful to have a good cell with a tablet.
The A53 5G is going to have way more updates than the S6... Also i've had mine since a week after it came out from T-Mobile and i can honestly say this is the best phone i've ever owned. I know it's a mid range phone, but that's all i ever buy, because i have never felt the need to spend over a thousand dollars for a phone that's not really going to much more than a mid range phone from the same company. But anyway i love this A53 and there's no way the S6 can compare to this phone. Especially with the updates and security patches that it will receive compared to the S6