Rental income is good when you start but as the time goes the increment in rent doesn't go as the market price and after few years you will not be happy with the outcome. Secondly it will be a headache if the tenant decide not to leave the place or just starts paying rent in court. My father was a well known civil lawyer and he would tell me countless such cases.
The rent that look good today - will look bad after 5 years - will look worse after10 years - will look pathetic after 15 years
You are confusing between Modern Day Rental Agreement called
Leave & License with Olden Days Rent called
Pagdi System
Leave & License is safe, at least in Maharashtra (Mumbai/Thane/Palghar/Navi Mumbai etc.) 75% of flats in this region are on Leave & License and on completion of agreement, owner/tenant either Renew/Leave on mutual consents without any glitch etc.
Even in between agreement period either tenant or owner if think otherwise, after giving 30 days advance notice in writing, any one can cancel the agreement and move on.
I know people who pay 100rs rent for a main road shop where as present value of same shop is 5k, There are few extreme ones too where people pay 13rs ~15rs as rent for 30yr or 40yr old houses on rent.
it's called Pagdi System and that applicable in Chawl/Chaal type building.
Most of time 5-10 family/room have 1 common Latrine and in office time, hard to find vacant/empty latrine as all office goers need to use same 1 Latrine, so you may find long Que for Latrine in between Office goers.
On name of bathroom there is 3 feet x 3 feet mori but separate for each room inside room, still have same type Chawal in Mumbai till today and people keep living in ......
Owners of such pagdi system building (max 4 floors building and very very old, say 40-50 yrs or more) not allow any one to repair such building and keep wishing to let building collapse and let all die inside and once all matter settles, start building big posh towers (forget about what Law & Pagdi System Law saying)