It technically won't be for nothing - it will give you an exemption for SQE1 which means you could skip some of the prep (probably do a shorter prep course just focused on SQE2) and would obviously not have to pay out for the SQE 1 exams or prep course.
I just think this is a really expensive and time consuming way of getting an exemption.
Most firms are moving to the SQE by 2023 or 2024 because there will be such a small pipeline of talent who are still eligible to take the LPC route by 2024. By 2023 no non-law grads will be able to qualify via the LPC route unless they have done a part-time GDL or have deferred exams. In addition, many firms are not offering the option of how to qualify for those who have got a choice because trainees could ultimately be dealt with very differently. It is easier for many firms to just transition everyone over to the SQE to ensure consistency in how the trainees are managed.
I think my advice is to hold off until the late summer before making any decisions. LPC providers are notorious for piling on the pressure for you to commit early but put frankly, they never sell these courses out, and will really struggle to do so now the courses are on their way out. They are always advertising the courses weeks before they start in the late summer/early autumn. They will often try to sell the courses with early discounts etc to get people to commit when ultimately there is no need to do this. I would continue applying over the summer, see how your applications go, and then make a decision as to whether the LPC or the SQE is the right route for you.
If you go into the autumn recruitment cycle, a lot of firms will be recruiting for 2024/25 by that point, and I think it would be worthwhile checking which firms you want to apply to and whether they have moved across to the SQE or not to help inform your decision on what to do.