There is a lot of different views on this.  Do you think it is necessary?

What Is Training To Failure?
In weight training, training to failure is repeating an exercise (such as the bench press) to the point of momentary muscular failure, i.e. the point where a repetition fails due to inadequate muscular strength.

What Is A Muscle Failure?

Muscle failure is the point when your working muscle is fully fatigued to the extent that it can no longer complete another repetition of a movement with strict biomechanics.

So Now You Know What It Is!
Take a look, and tell us what you think?

References for video:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4731492/
https://www.ncbi.nlm.nih.gov/pubmed/25809472
http://sci-hub.cc/10.1111/sms.12445
https://www.ncbi.nlm.nih.gov/pubmed/17530977
https://www.ncbi.nlm.nih.gov/pubmed/15903379
https://www.ncbi.nlm.nih.gov/pubmed/26270694/
http://sci-hub.cc/10.1152/japplphysiol.01400.2005
http://www.bio.unipd.it/bam/PDF/27-2/Martorelli.pdf
https://www.ncbi.nlm.nih.gov/pubmed/27218448
http://sci-hub.cc/10.1152/japplphysiol.90538.2008
http://sci-hub.cc/10.1519/JSC.0000000000000958
http://sci-hub.cc/10.1007/s00421-014-2976-9