What are drawbacks of SEO?
 

It takes a lot of time for SEO to show effects

Long wait to get ROI

To be competitive, it requires a lot of investment

There?s no assurance that it will work for sure

Left at the mercy of an algorithm

You can be penalized

ya as you said it takes time to show its result

It takes a lot of time show result.

HI

The biggest disadvantage of SEO is you cannot quickly reduce your sales or leads for a few weeks if they have built up too quickly.

https://www.welllivingshop.com/pillows/

The biggest disadvantage is that it will take loads of time for it to pay up...

You can be penalized for any mistake
It takes a lot of time for SEO to show results
Long wait to get ROI
To be competitive, it require a lot of investment
There’s no assurance that it will work for sure
Left at the mercy of an algorithm

i don't think so that seo have any drawbacks. SEO is the best technique to rank on page 1 in google. every one should use seo techniques to get online business.