I'm an investor in Philadelphia, and after having done 2 recent full guts in the area I will attest to that being a lot of effort and risk. It is very competitive in Philly right now, and the remaining properties tend to be extremely old and bring with them a high risk of foundational issues which can put you in the hole pretty quickly.
If you're going to take on the risk of a full rehab, make sure it's worth your time and risk. In this case, I would say it is definitely not good for a buy and hold.
Others have touched on the flip side of this above (I agree not a great flip either), but here are the numbers from my Philly market analyzer using a hard money/private money lender and then refinancing out for 75% afterwards with 6 months of construction (which is probably not long enough for that job given how slow Philly License and Inspection department is taking with Covid).
Note I used the low end on the ARV and high end on the rehab, which is what I would always recommend when starting to analyze a deal (aim to be on the conservative side).
As you can see, you'd bring about 11k to the table initially and then at the refinance would likely have to bring another 3-5k to the table and would not be cash flowing at all (basically 0% cash on cash return). I would never do this deal for a buy and hold.
For reference, I only even start to look at deals when I'm making $350+/month and have at least a 20%+