Yes, the availability of High-speed internet will be a major drawback in the Internet of Things development and implementation because it is one of the major requirement for the Internet of things to work efficiently and effectively. @Kajal

The Internet of Things can be organized on the basis of low-speed, low-power networks using the LORAVAN protocol — created by Semtech Corporation and IBM Research Research Center in 2015.

it's depend of the technology used is IoT in radio part : for example SIGFOX, LoRa, cIoT, NB IoT also depend of Range (coverage); spectrum Bandwidth and data rate.

So High Speed Throughput is not necessary drawback in IoT development and implementation Kajal Panda