I've been fairly non-active on this site for a while as I work on my undergrad studies and spend a lot of time thinking about novels I haven't bothered to write, and patter about in the forums so first of all, well done writing anything at all and posting it. Completing something and putting it out there for response is a difficult first step, and one many potential writers never achieve. (I refer again to my own very empty portfolio and very scarce activity as a reviewer.)
As you're weighing the pros and cons in your decision, you might consider:
1) that reviewing others' work here can strengthen your own work by offering context and exercising your mind.*
2) that reading published works does the same, even if you find the activity arduous. If you choose to quit the site, my advice is to go to the library and overcome your dislike of reading, immediately. Power through it until you conquer books.
3) that by my count you've given 21 reviews since you joined, and received 24 back. I don't know if I've calculated that right, since I believe reviews disappear if people delete their work. But if what I'm reading is nearly accurate, you have actually done very well on the site. A lot of the reviews you've given have been since April 2017, and a lot of the reciprocated reviews have been since April 2017. You've given 7 reviews in the last three weeks and have gotten 10 back, by my count -- not 2? That includes a few by Marilyn Johnson since this forum post was written seeking additional feedback. It seems like you're planning to base your entire assessment of the site on the response-time of less than a month.
I've been on this site for a while, & have seen people post in a flurry and leave as quickly, claiming disappointment with the scarce response to their work. Sometimes leaving is exactly the right choice. For example, when a writer lacks confidence or a sense of what he or she intends to write, opposing reviews can be extremely confusing and push out the writer's own viewpoint. I see this a lot when people post a work in progress rather than a completed work. The story starts to be written according to the reviewers' opposing tastes rather than the author's, leaving the author dissatisfied and lost. Certainly not what you want! It doesn't sound like that's your issue though: you seem to be extremely confident about your work and just crave more feedback. I expect that's the lot of many writers. There will be peaks and troughs in the writer's journey. The troughs can be frustrating. Only you can decide how best to respond to them.
If you think leaving the site is the best way to achieve success as a writer, I don't think anyone here will try to stop you. Most here would want to see you succeed.
Very best wishes, however, you choose to proceed.
* Although one of the site's new perks seems to be that a person can review for free when the work is visible to a wide audience of non-paying members. So (if I understand things correctly) you can still do some piping good reviewing exercises as a non-paying member! You don't even have to post your remarks, if you don't want to. You can do that privately, for exercise. I humbly suggest that you've gotten something out of writing reviews even if it wasn't the sort of feedback you wanted or expected when you joined.