If a club doesn't fight harder, the relegation zone becomes a spot to deal with. Brentford will hosts Chelsea this weekend at their home ground stadium. An important win for Chelsea because they have no good records against the home team but fighting harder wouldn't do any significant pressure. Brentford have suffered crucial defeats in their previous games and this have become a thing to worry about. The Bees headcoach, Thomas Frank will become an ultimate pillar for the club, he's not responding nicely to the present condition of the club.
A club can work hard and still get relegated because other people that are in the competition are far ahead and stronger than them. Look at Luton town, Burnley and Sheff united. They were recently promoted after winning the top 3 in the Championship to the Premier League but because they are not used to how Premier League is been played, they are not winning matches like other teams and the are sitting below relegation zone.
Another could be as result of unexpected circumstances, Everton is a living testimony of these. They got there points has been deducted by 10 because of financial fair play of 2020 and they were demoted down in the table to relegation zone but they are trying their best to remained solid and unbothered because they are now in number 15th place in the table. If not for this point deduction, they should be above Chelsea or even more but because of that deduction, they didn't perform to their full potential.