I've had a TIN for 15 years now. I needed it to open a bank account (as I recall). The bank needed a TIN so the BIR could collect their taxes on what little interest my bank account generates.
You do not need to file a tax return or have any interaction with BIR. If you have income abroad (or a pension) that is not taxed here. The BIR treats overseas income like they treat OFWs (offshore foreign workers) is not taxed.