It's obviously not going to be anywhere near as lucrative as in the past.
Your mortgage will be far more expensive than in the last 15 years.
There's probably not much hope of capital growth in the short to medium term and you could likely lose some of the value of your capital.
If you already own a property there's additional stamp duty to pay.
And that's before the income tax rules that are stricter than the 'money for old rope' days and forthcoming changes to EPC rules.
Plus it's likely that you'll earn more money on savings interest going forward, which increases the bar above which it's 'worth it'.
BTL might be worth it in areas of high rental demand if you manage to get the right property at the right price and have the time and contacts to be a landlord (repairs etc).
But at the other end of the scale it can be a lot of hassle for little or no reward, if interest rates increase, you have voids, your tenants don't pay/trash the property, you need to replace the boiler etc etc.